diff --git a/admin-dev/themes/default/template/controllers/products/combinations.tpl b/admin-dev/themes/default/template/controllers/products/combinations.tpl
index 030474776..38f12a050 100644
--- a/admin-dev/themes/default/template/controllers/products/combinations.tpl
+++ b/admin-dev/themes/default/template/controllers/products/combinations.tpl
@@ -55,13 +55,18 @@
 	<h4>{l s='Add or modify combinations for this product'}</h4>
 	<div class="separation"></div> {l s='or go to'}
 		&nbsp;<a class="button bt-icon confirm_leave" href="index.php?tab=AdminAttributeGenerator&id_product={$product->id}&attributegenerator&token={$token_generator}"><img src="../img/admin/appearance.gif" alt="combinations_generator" class="middle" title="{l s='Product combinations generator'}" /><span>{l s='Product combinations generator'}</span></a>
+
+	{if isset($display_multishop_checkboxes) && $display_multishop_checkboxes}
+		<br />
+		{include file="controllers/products/multishop/check_fields.tpl" product_tab="Combinations"}
+	{/if}
 	<div class="separation"></div>
 	
 	<div id="add_new_combination" style="display: none;">
 		<table cellpadding="5" style="width:100%">
 			<tr>
 				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;" valign="top">
-					{l s='Attribute:'}
+					<label>{l s='Attribute:'}</label>
 				</td>
 				<td style="padding-bottom:5px;">
 					<select name="attribute_group" id="attribute_group" style="width: 200px;" onchange="populate_attrs();">
@@ -75,7 +80,7 @@
 			</tr>
 			<tr>
 				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;" valign="top">
-					{l s='Value:'}
+					<label>{l s='Value:'}</label>
 				</td>
 				<td style="padding-bottom:5px;">
 					<select name="attribute" id="attribute" style="width: 200px;">
@@ -102,7 +107,7 @@
 				</td>
 			</tr>
 			<tr>
-				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;">{l s='Reference:'}</td>
+				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;"><label>{l s='Reference:'}</label></td>
 				<td style="padding-bottom:5px;">
 					<input size="55" type="text" id="attribute_reference" name="attribute_reference" value="" style="width: 130px; margin-right: 44px;" />
 					{l s='EAN13:'}<input size="55" maxlength="13" type="text" id="attribute_ean13" name="attribute_ean13" value="" style="width: 110px; margin-left: 10px; margin-right: 44px;" />
@@ -175,7 +180,8 @@
 		<table>
 			<tr>
 				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;">
-					{l s='Wholesale price:'}
+					{include file="controllers/products/multishop/checkbox.tpl" field="attribute_wholesale_price" type="default"}
+					<label>{l s='Wholesale price:'}</label>
 				</td>
 				<td style="padding-bottom:5px;">
 					{if $currency->format % 2 != 0}{$currency->sign}{/if}
@@ -185,7 +191,10 @@
 				</td>
 			</tr>
 			<tr>
-				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;">{l s='Impact on price:'}</td>
+				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;">
+					{include file="controllers/products/multishop/checkbox.tpl" field="attribute_price_impact" type="attribute_price_impact"}
+					<label>{l s='Impact on price:'}</label>
+				</td>
 				<td colspan="2" style="padding-bottom:5px;">
 					<select name="attribute_price_impact" id="attribute_price_impact" style="width: 140px;" onchange="check_impact(); calcImpactPriceTI();">
 						<option value="0">{l s='None'}</option>
@@ -210,7 +219,10 @@
 				</td>
 			</tr>
 			<tr>
-				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;">{l s='Impact on weight:'}</td>
+				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;">
+					{include file="controllers/products/multishop/checkbox.tpl" field="attribute_weight_impact" type="attribute_weight_impact"}
+					<label>{l s='Impact on weight:'}</label>
+				</td>
 				<td colspan="2" style="padding-bottom:5px;">
 					<select name="attribute_weight_impact" id="attribute_weight_impact" style="width: 140px;" onchange="check_weight_impact();">
 						<option value="0">{l s='None'}</option>
@@ -224,7 +236,10 @@
 				</td>
 			</tr>
 			<tr id="tr_unit_impact">
-				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;">{l s='Impact on unit price :'}</td>
+				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;">
+					{include file="controllers/products/multishop/checkbox.tpl" field="attribute_unit_impact" type="attribute_unit_impact"}
+					<label style="width: 100px; float: right">{l s='Impact on unit price :'}</label>
+				</td>
 				<td colspan="2" style="padding-bottom:5px;">
 					<select name="attribute_unit_impact" id="attribute_unit_impact" style="width: 140px;" onchange="check_unit_impact();">
 						<option value="0">{l s='None'}</option>
@@ -240,7 +255,8 @@
 			{if $ps_use_ecotax}
 				<tr>
 					<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;">
-						{l s='Eco-tax:'}
+						{include file="controllers/products/multishop/checkbox.tpl" field="attribute_ecotax" type="default"}
+						<label>{l s='Eco-tax:'}</label>
 					</td>
 					<td style="padding-bottom:5px;">{if $currency->format % 2 != 0}{$currency->sign}{/if}
 						<input type="text" size="3" name="attribute_ecotax" id="attribute_ecotax" value="0.00" onKeyUp="if (isArrowKey(event)) return ;this.value = this.value.replace(/,/g, '.');" />
@@ -251,6 +267,7 @@
 			{/if}
 			<tr>
 				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;" class="col-left">
+					{include file="controllers/products/multishop/checkbox.tpl" field="attribute_minimal_quantity" type="default"}
 					<label>{l s='Minimum quantity:'}</label>
 				</td>
 				<td style="padding-bottom:5px;">
@@ -259,7 +276,8 @@
 				</td>
 			</tr>
 			<tr>
-				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;" class="col-left" style="width:150px">
+				<td style="width:150px;vertical-align:top;text-align:right;padding-right:10px;font-weight:bold;" class="col-left">
+					{include file="controllers/products/multishop/checkbox.tpl" field="available_date_attribute" type="default"}
 					<label>{l s='Available date:'}</label>
 				</td>
 				<td style="padding-bottom:5px;">
@@ -282,7 +300,7 @@
 				</td>
 			</tr>
 			<tr>
-				<td style="width:150px">{l s='Image:'}</td>
+				<td style="width:150px"><label>{l s='Image:'}</label></td>
 				<td style="padding-bottom:5px;">
 					<ul id="id_image_attr">
 						{foreach from=$images key=k item=image}
@@ -298,7 +316,10 @@
 				</td>
 			</tr>
 			<tr>
-				<td style="width:150px">{l s='Default:'}<br /><br /></td>
+				<td style="width:150px">
+					{include file="controllers/products/multishop/checkbox.tpl" field="attribute_default" type="attribute_default"}
+					<label>{l s='Default:'}</label><br /><br />
+				</td>
 				<td style="padding-bottom:5px;">
 					<input type="checkbox" name="attribute_default" id="attribute_default" value="1" />
 					&nbsp;{l s='Make this the default combination for this product'}<br /><br />
diff --git a/admin-dev/themes/default/template/controllers/products/helpers/form/form.tpl b/admin-dev/themes/default/template/controllers/products/helpers/form/form.tpl
index fce48bbe1..9f7827389 100644
--- a/admin-dev/themes/default/template/controllers/products/helpers/form/form.tpl
+++ b/admin-dev/themes/default/template/controllers/products/helpers/form/form.tpl
@@ -44,9 +44,9 @@
 
 					ed.onInit.add(function(ed)
 					{
-						if (typeof load_tinymce_multishop[ed.id] != 'undefined')
+						if (typeof ProductMultishop.load_tinymce[ed.id] != 'undefined')
 						{
-							if (typeof load_tinymce_multishop[ed.id])
+							if (typeof ProductMultishop.load_tinymce[ed.id])
 								ed.hide();
 							else
 								ed.show();
diff --git a/admin-dev/themes/default/template/controllers/products/multishop/check_fields.tpl b/admin-dev/themes/default/template/controllers/products/multishop/check_fields.tpl
index d3e34b435..414c1340d 100644
--- a/admin-dev/themes/default/template/controllers/products/multishop/check_fields.tpl
+++ b/admin-dev/themes/default/template/controllers/products/multishop/check_fields.tpl
@@ -26,7 +26,7 @@
 
 {if isset($display_multishop_checkboxes) && $display_multishop_checkboxes}
 	<label style="float: none">
-		<input type="checkbox" style="vertical-align: text-bottom" onclick="$('input[name^=\'multishop_check[\']').attr('checked', this.checked); multishopCheckAllProductFields{$product_tab}()" />
+		<input type="checkbox" style="vertical-align: text-bottom" onclick="$('input[name^=\'multishop_check[\']').attr('checked', this.checked); ProductMultishop.checkAll{$product_tab}()" />
 		{l s='Check / uncheck all (you are editing this page for several shops, some fields like "name" or "price" are disabled, you have to check these fields in order to edit them for these shops)'}
 	</label>
 {/if}
\ No newline at end of file
diff --git a/admin-dev/themes/default/template/controllers/products/multishop/checkbox.tpl b/admin-dev/themes/default/template/controllers/products/multishop/checkbox.tpl
index b5463ced5..362ff030b 100644
--- a/admin-dev/themes/default/template/controllers/products/multishop/checkbox.tpl
+++ b/admin-dev/themes/default/template/controllers/products/multishop/checkbox.tpl
@@ -28,23 +28,23 @@
 	{if isset($multilang) && $multilang}
 		{if isset($only_checkbox)}
 			{foreach from=$languages item=language}
-				<input type="checkbox" name="multishop_check[{$field}][{$language.id_lang}]" value="1" onclick="multishopCheckProductField(this.checked, '{$field}_{$language.id_lang}', '{$type}')" {if !empty($multishop_check[$field][$language.id_lang])}checked="checked"{/if} />
+				<input type="checkbox" name="multishop_check[{$field}][{$language.id_lang}]" value="1" onclick="ProductMultishop.checkField(this.checked, '{$field}_{$language.id_lang}', '{$type}')" {if !empty($multishop_check[$field][$language.id_lang])}checked="checked"{/if} />
 			{/foreach}
 		{else}
 			<div class="multishop_product_checkbox">
 				{foreach from=$languages item=language}
 					<div class="multishop_lang_{$language.id_lang}" style="{if !$language.is_default}display: none;{/if}">
-						<input type="checkbox" name="multishop_check[{$field}][{$language.id_lang}]" value="1" onclick="multishopCheckProductField(this.checked, '{$field}_{$language.id_lang}', '{$type}')" {if !empty($multishop_check[$field][$language.id_lang])}checked="checked"{/if} />
+						<input type="checkbox" name="multishop_check[{$field}][{$language.id_lang}]" value="1" onclick="ProductMultishop.checkField(this.checked, '{$field}_{$language.id_lang}', '{$type}')" {if !empty($multishop_check[$field][$language.id_lang])}checked="checked"{/if} />
 					</div>
 				{/foreach}
 			</div>
 		{/if}
 	{else}
 		{if isset($only_checkbox)}
-			<input type="checkbox" name="multishop_check[{$field}]" value="1" onclick="multishopCheckProductField(this.checked, '{$field}', '{$type}')" {if !empty($multishop_check[$field])}checked="checked"{/if} />
+			<input type="checkbox" name="multishop_check[{$field}]" value="1" onclick="ProductMultishop.checkField(this.checked, '{$field}', '{$type}')" {if !empty($multishop_check[$field])}checked="checked"{/if} />
 		{else}
 			<div class="multishop_product_checkbox">
-				<input type="checkbox" name="multishop_check[{$field}]" value="1" onclick="multishopCheckProductField(this.checked, '{$field}', '{$type}')" {if !empty($multishop_check[$field])}checked="checked"{/if} />
+				<input type="checkbox" name="multishop_check[{$field}]" value="1" onclick="ProductMultishop.checkField(this.checked, '{$field}', '{$type}')" {if !empty($multishop_check[$field])}checked="checked"{/if} />
 			</div>
 		{/if}
 	{/if}
diff --git a/admin-dev/themes/default/template/controllers/products/prices.tpl b/admin-dev/themes/default/template/controllers/products/prices.tpl
index def8fed5f..5c14545a1 100644
--- a/admin-dev/themes/default/template/controllers/products/prices.tpl
+++ b/admin-dev/themes/default/template/controllers/products/prices.tpl
@@ -174,7 +174,10 @@ jQuery(document).ready(Customer.init);
 	</tr>
 	{if $ps_use_ecotax}
 		<tr>
-			<td class="col-left"><label>{l s='Eco-tax (tax incl.):'}</label></td>
+			<td class="col-left">
+				{include file="controllers/products/multishop/checkbox.tpl" field="ecot" type="default"}
+				<label>{l s='Eco-tax (tax incl.):'}</label>
+			</td>
 			<td>
 				{$currency->prefix}<input size="11" maxlength="14" id="ecotax" name="ecotax" type="text" value="{$product->ecotax|string_format:'%.2f'}" onkeyup="$('#priceType').val('TI');if (isArrowKey(event))return; calcPriceTE(); this.value = this.value.replace(/,/g, '.'); if (parseInt(this.value) > getE('priceTE').value) this.value = getE('priceTE').value; if (isNaN(this.value)) this.value = 0;" />{$currency->suffix}
 				<span style="margin-left:10px">({l s='already included in price'})</span>
diff --git a/classes/Combination.php b/classes/Combination.php
index 73d18af3d..391506ec5 100644
--- a/classes/Combination.php
+++ b/classes/Combination.php
@@ -70,7 +70,6 @@ class CombinationCore extends ObjectModel
 			'ean13' => 				array('type' => self::TYPE_STRING, 'validate' => 'isEan13', 'size' => 13),
 			'upc' => 				array('type' => self::TYPE_STRING, 'validate' => 'isUpc', 'size' => 12),
 			'quantity' => 			array('type' => self::TYPE_INT, 'validate' => 'isUnsignedInt', 'size' => 10),
-			'weight' => 			array('type' => self::TYPE_INT, 'validate' => 'isFloat'),
 			'reference' => 			array('type' => self::TYPE_STRING, 'size' => 32),
 			'supplier_reference' => array('type' => self::TYPE_STRING, 'size' => 32),
 
@@ -78,6 +77,7 @@ class CombinationCore extends ObjectModel
 			'wholesale_price' =>	array('type' => self::TYPE_FLOAT, 'shop' => true, 'validate' => 'isPrice', 'size' => 27),
 			'price' => 				array('type' => self::TYPE_FLOAT, 'shop' => true, 'validate' => 'isNegativePrice', 'size' => 20),
 			'ecotax' => 			array('type' => self::TYPE_FLOAT, 'shop' => true, 'validate' => 'isPrice', 'size' => 20),
+			'weight' => 			array('type' => self::TYPE_FLOAT, 'shop' => true, 'validate' => 'isFloat'),
 			'unit_price_impact' => 	array('type' => self::TYPE_FLOAT, 'shop' => true, 'validate' => 'isPrice', 'size' => 20),
 			'minimal_quantity' => 	array('type' => self::TYPE_INT, 'shop' => true, 'validate' => 'isUnsignedId', 'required' => true),
 			'default_on' => 		array('type' => self::TYPE_INT, 'shop' => true, 'validate' => 'isBool'),
diff --git a/classes/ObjectModel.php b/classes/ObjectModel.php
index a5d16f554..1d8b5b8e6 100644
--- a/classes/ObjectModel.php
+++ b/classes/ObjectModel.php
@@ -339,8 +339,9 @@ abstract class ObjectModelCore
 				|| ($type == self::FORMAT_COMMON && (!empty($data['shop']) || !empty($data['lang']))))
 				continue;
 
-			if (is_array($this->update_fields) && (empty($this->update_fields[$field]) || ($type == self::FORMAT_LANG && empty($this->update_fields[$field][$id_lang]))))
-				continue;
+			if (is_array($this->update_fields))
+				if ((!empty($data['lang']) || !empty($data['shop'])) && (empty($this->update_fields[$field]) || ($type == self::FORMAT_LANG && empty($this->update_fields[$field][$id_lang]))))
+					continue;
 
 			// Get field value, if value is multilang and field is empty, use value from default lang
 			$value = $this->$field;
@@ -433,12 +434,7 @@ abstract class ObjectModelCore
 			$this->date_upd = date('Y-m-d H:i:s');
 
 		// Database insertion
-		if ($null_values)
-			$result = Db::getInstance()->insert($this->def['table'], $this->getFields(), true);
-		else
-			$result = Db::getInstance()->insert($this->def['table'], $this->getFields());
-
-		if (!$result)
+		if (!$result = Db::getInstance()->insert($this->def['table'], $this->getFields(), $null_values))
 			return false;
 
 		// Get object id in database
@@ -450,10 +446,7 @@ abstract class ObjectModelCore
 			$fields = $this->getFieldsShop();
 			$fields[$this->def['primary']] = (int)$this->id;
 			$fields['id_shop'] = (int)$this->id_shop;
-			if ($null_values)
-				$result &= Db::getInstance()->insert($this->def['table'].'_shop', $fields, true);
-			else
-				$result &= Db::getInstance()->insert($this->def['table'].'_shop', $fields);
+			$result &= Db::getInstance()->insert($this->def['table'].'_shop', $fields, $null_values);
 		}
 		else if (!Shop::isFeatureActive() && Shop::isTableAssociated($this->def['table']))
 			$result &= $this->associateTo(Context::getContext()->shop->id);
@@ -515,12 +508,7 @@ abstract class ObjectModelCore
 			$this->date_upd = date('Y-m-d H:i:s');
 
 		// Database update
-		if ($null_values)
-			$result = Db::getInstance()->update($this->def['table'], $this->getFields(), '`'.pSQL($this->def['primary']).'` = '.(int)$this->id, 0, true);
-		else
-			$result = Db::getInstance()->update($this->def['table'], $this->getFields(), '`'.pSQL($this->def['primary']).'` = '.(int)$this->id);
-
-		if (!$result)
+		if (!$result = Db::getInstance()->update($this->def['table'], $this->getFields(), '`'.pSQL($this->def['primary']).'` = '.(int)$this->id, 0, $null_values))
 			return false;
 
 		// Database insertion for multishop fields related to the object
@@ -528,14 +516,26 @@ abstract class ObjectModelCore
 		{
 			$fields = $this->getFieldsShop();
 			$fields[$this->def['primary']] = (int)$this->id;
+			if (is_array($this->update_fields))
+			{
+				$update_fields = $this->update_fields;
+				$this->update_fields = null;
+				$all_fields = $this->getFieldsShop();
+				$all_fields[$this->def['primary']] = (int)$this->id;
+				$this->update_fields = $update_fields;
+			}
+			else
+				$all_fields = $fields;
+
 			foreach (Shop::getContextListShopID() as $id_shop)
 			{
 				$fields['id_shop'] = $id_shop;
+				$all_fields['id_shop'] = $id_shop;
 				$where = $this->def['primary'].' = '.(int)$this->id.' AND id_shop = '.(int)$id_shop;
 				if (Db::getInstance()->getValue('SELECT '.$this->def['primary'].' FROM '._DB_PREFIX_.$this->def['table'].'_shop WHERE '.$where))
 					$result &= Db::getInstance()->update($this->def['table'].'_shop', $fields, $where, 0, $null_values);
 				else
-					$result &= Db::getInstance()->insert($this->def['table'].'_shop', $fields, $null_values);
+					$result &= Db::getInstance()->insert($this->def['table'].'_shop', $all_fields, $null_values);
 			}
 		}
 
diff --git a/classes/Product.php b/classes/Product.php
index 92ce273d1..283cd78a0 100644
--- a/classes/Product.php
+++ b/classes/Product.php
@@ -1231,12 +1231,25 @@ class ProductCore extends ObjectModel
 	* @return array Update result
 	*/
 	public function updateAttribute($id_product_attribute, $wholesale_price, $price, $weight, $unit, $ecotax,
-		$id_images, $reference, $ean13, $default, $location = null, $upc = null, $minimal_quantity, $available_date)
+		$id_images, $reference, $ean13, $default, $location = null, $upc = null, $minimal_quantity = null, $available_date = null, $update_all_fields = true)
 	{
+		$combination = new Combination($id_product_attribute);
+
+		if (!$update_all_fields)
+			$combination->setFieldsToUpdate(array(
+				'price' => !is_null($price),
+				'wholesale_price' => !is_null($wholesale_price),
+				'ecotax' => !is_null($ecotax),
+				'weight' => !is_null($weight),
+				'unit_price_impact' => !is_null($unit),
+				'default_on' => !is_null($ecotax),
+				'minimal_quantity' => !is_null($minimal_quantity),
+				'available_date' => !is_null($available_date),
+			));
+
 		$price = str_replace(',', '.', $price);
 		$weight = str_replace(',', '.', $weight);
 
-		$combination = new Combination($id_product_attribute);
 		$combination->price = (float)$price;
 		$combination->wholesale_price = (float)$wholesale_price;
 		$combination->ecotax = (float)$ecotax;
@@ -1248,7 +1261,8 @@ class ProductCore extends ObjectModel
 		$combination->upc = pSQL($upc);
 		$combination->default_on = (int)$default;
 		$combination->minimal_quantity = (int)$minimal_quantity;
-		$combination->available_date = pSQL($available_date);
+		$combination->available_date = $available_date ? pSQL($available_date) : '0000-00-00';
+
 		$combination->save();
 
 		if (!empty($id_images))
diff --git a/controllers/admin/AdminProductsController.php b/controllers/admin/AdminProductsController.php
index 636d698bb..7f8fe2e06 100644
--- a/controllers/admin/AdminProductsController.php
+++ b/controllers/admin/AdminProductsController.php
@@ -583,7 +583,7 @@ class AdminProductsControllerCore extends AdminController
 
 		if (Validate::isLoadedObject($product = $this->object))
 		{
-			if (!Tools::getIsset('attribute_price') || Tools::getIsset('attribute_price') == null)
+			if ($this->isProductFieldUpdated('attribute_price') && (!Tools::getIsset('attribute_price') || Tools::getIsset('attribute_price') == null))
 				$this->errors[] = Tools::displayError('Attribute price required.');
 			if (!Tools::getIsset('attribute_combination_list') || Tools::isEmpty(Tools::getValue('attribute_combination_list')))
 				$this->errors[] = Tools::displayError('You must add at least one attribute.');
@@ -605,28 +605,29 @@ class AdminProductsControllerCore extends AdminController
 							$this->errors[] = Tools::displayError('This attribute already exists.');
 						else
 						{
-							if (Validate::isDateFormat(Tools::getValue('available_date_attribute')))
+							if ($this->isProductFieldUpdated('available_date_attribute') && !Validate::isDateFormat(Tools::getValue('available_date_attribute')))
+								$this->errors[] = Tools::displayError('Invalid date format.');
+							else
 							{
 								$product->updateAttribute((int)$id_product_attribute,
-									Tools::getValue('attribute_wholesale_price'),
-									Tools::getValue('attribute_price') * Tools::getValue('attribute_price_impact'),
-									Tools::getValue('attribute_weight') * Tools::getValue('attribute_weight_impact'),
-									Tools::getValue('attribute_unity') * Tools::getValue('attribute_unit_impact'),
-									Tools::getValue('attribute_ecotax'),
+									$this->isProductFieldUpdated('attribute_wholesale_price') ? Tools::getValue('attribute_wholesale_price') : null,
+									$this->isProductFieldUpdated('attribute_price_impact') ? Tools::getValue('attribute_price') * Tools::getValue('attribute_price_impact') : null,
+									$this->isProductFieldUpdated('attribute_weight_impact') ? Tools::getValue('attribute_weight') * Tools::getValue('attribute_weight_impact') : null,
+									$this->isProductFieldUpdated('attribute_unit_impact') ? Tools::getValue('attribute_unity') * Tools::getValue('attribute_unit_impact') : null,
+									$this->isProductFieldUpdated('attribute_ecotax') ? Tools::getValue('attribute_ecotax') : null,
 									Tools::getValue('id_image_attr'),
 									Tools::getValue('attribute_reference'),
 									Tools::getValue('attribute_ean13'),
-									Tools::getValue('attribute_default'),
+									$this->isProductFieldUpdated('attribute_default') ? Tools::getValue('attribute_default') : null,
 									Tools::getValue('attribute_location'),
 									Tools::getValue('attribute_upc'),
-									Tools::getValue('attribute_minimal_quantity'),
-									Tools::getValue('available_date_attribute'));
+									$this->isProductFieldUpdated('attribute_minimal_quantity') ? Tools::getValue('attribute_minimal_quantity') : null,
+									$this->isProductFieldUpdated('available_date_attribute') ? Tools::getValue('available_date_attribute') : null,
+									false);
 
 								Hook::exec('actionProductAttributeUpdate', array('id_product_attribute' => (int)$id_product_attribute));
 								$this->updateDownloadProduct($product, 1, $id_product_attribute);
 							}
-							else
-								$this->errors[] = Tools::displayError('Invalid date format.');
 						}
 					}
 					else
@@ -1552,9 +1553,7 @@ class AdminProductsControllerCore extends AdminController
 					if ($this->isTabSubmitted('Shipping'))
 						$this->addCarriers();
 					if ($this->isTabSubmitted('Associations'))
-					{
 						$this->updateAccessories($object);
-					}
 
 					if ($this->isTabSubmitted('Accounting'))
 						$this->processAccounting();
@@ -1727,7 +1726,7 @@ class AdminProductsControllerCore extends AdminController
 		// Cache this condition to improve performances
 		static $is_activated = null;
 		if (is_null($is_activated))
-			$is_activated = Shop::isFeatureActive() && Shop::getContext() != Shop::CONTEXT_SHOP;
+			$is_activated = Shop::isFeatureActive() && Shop::getContext() != Shop::CONTEXT_SHOP && $this->id_object;
 
 		if (!$is_activated)
 			return true;
diff --git a/install-dev/data/db_structure.sql b/install-dev/data/db_structure.sql
index 8386da7ea..4a3e2b5cb 100644
--- a/install-dev/data/db_structure.sql
+++ b/install-dev/data/db_structure.sql
@@ -1447,6 +1447,7 @@ CREATE TABLE `PREFIX_product_attribute_shop` (
   `wholesale_price` decimal(20,6) NOT NULL default '0.000000',
   `price` decimal(20,6) NOT NULL default '0.000000',
   `ecotax` decimal(17,6) NOT NULL default '0.00',
+  `weight` float NOT NULL default '0',
   `unit_price_impact` decimal(17,2) NOT NULL default '0.00',
   `default_on` tinyint(1) unsigned NOT NULL default '0',
   `minimal_quantity` int(10) unsigned NOT NULL DEFAULT '1',
diff --git a/install-dev/upgrade/sql/1.5.0.10.sql b/install-dev/upgrade/sql/1.5.0.10.sql
index 3af0b5e47..0e7762abc 100644
--- a/install-dev/upgrade/sql/1.5.0.10.sql
+++ b/install-dev/upgrade/sql/1.5.0.10.sql
@@ -61,13 +61,14 @@ CREATE TABLE `PREFIX_product_attribute_shop` (
   `wholesale_price` decimal(20,6) NOT NULL default '0.000000',
   `price` decimal(20,6) NOT NULL default '0.000000',
   `ecotax` decimal(17,6) NOT NULL default '0.00',
+  `weight` float NOT NULL default '0',
   `unit_price_impact` decimal(17,2) NOT NULL default '0.00',
   `default_on` tinyint(1) unsigned NOT NULL default '0',
   `minimal_quantity` int(10) unsigned NOT NULL DEFAULT '1',
   `available_date` date NOT NULL,
   PRIMARY KEY  (`id_product_attribute`, `id_shop`)
 ) ENGINE=ENGINE_TYPE DEFAULT CHARSET=utf8;
-INSERT INTO `PREFIX_product_attribute_shop` (`id_product_attribute`, `id_shop`, `wholesale_price`, `price`, `ecotax`, `unit_price_impact`, `default_on`, `minimal_quantity`, `available_date`) (SELECT `id_product_attribute`, (SELECT `value` FROM `PREFIX_configuration` WHERE `name` = 'PS_SHOP_DEFAULT'), `wholesale_price`, `price`, `ecotax`, `unit_price_impact`, `default_on`, `minimal_quantity`, `available_date` FROM `PREFIX_product_attribute`);
+INSERT INTO `PREFIX_product_attribute_shop` (`id_product_attribute`, `id_shop`, `wholesale_price`, `price`, `ecotax`, `weight`, `unit_price_impact`, `default_on`, `minimal_quantity`, `available_date`) (SELECT `id_product_attribute`, (SELECT `value` FROM `PREFIX_configuration` WHERE `name` = 'PS_SHOP_DEFAULT'), `wholesale_price`, `price`, `ecotax`, `weight`, `unit_price_impact`, `default_on`, `minimal_quantity`, `available_date` FROM `PREFIX_product_attribute`);
 
 INSERT INTO `PREFIX_attribute_shop` (`id_attribute`, `id_shop`) (SELECT a.id_attribute, c.id_shop FROM PREFIX_attribute_group_shop a LEFT JOIN PREFIX_shop_group b ON a.id_group_shop = b.id_shop_group INNER JOIN PREFIX_shop c ON b.id_shop_group = c.id_shop_group);
 CREATE TABLE `PREFIX_attribute_shop` (
diff --git a/js/admin-products.js b/js/admin-products.js
index ddff238e6..1fc17ec0b 100644
--- a/js/admin-products.js
+++ b/js/admin-products.js
@@ -398,6 +398,8 @@ product_tabs['Combinations'] = new function(){
 		self.bindDefault();
 		self.bindDelete();
 		self.bindToggleAddCombination();
+		if (display_multishop_checkboxes)
+			ProductMultishop.checkAllCombinations();
 	};
 }
 
@@ -507,7 +509,7 @@ product_tabs['Seo'] = new function(){
 		displayFlags(languages, id_language, allowEmployeeFormLang);
 
 		if (display_multishop_checkboxes)
-			multishopCheckAllProductFieldsSeo();
+			ProductMultishop.checkAllSeo();
 	};
 }
 
@@ -580,7 +582,7 @@ product_tabs['Prices'] = new function(){
 		self.bindDelete();
 
 		if (display_multishop_checkboxes)
-			multishopCheckAllProductFieldsPrice();
+			ProductMultishop.checkAllPrice();
 	};
 }
 
@@ -716,7 +718,7 @@ product_tabs['Associations'] = new function(){
 		});
 
 		if (display_multishop_checkboxes)
-			multishopCheckAllProductFieldsAssociations();
+			ProductMultishop.checkAllAssociations();
 	};
 }
 
@@ -931,7 +933,7 @@ product_tabs['Informations'] = new function(){
 
 		if (display_multishop_checkboxes)
 		{
-			multishopCheckAllProductFieldsInformations();
+			ProductMultishop.checkAllInformations();
 			var active_click = function()
 			{
 				if (!$('input[name=\'multishop_check[active]\']').attr('checked'))
@@ -1461,96 +1463,130 @@ function ajaxAction (url, action, success_callback, failure_callback){
 	});
 };
 
-var load_tinymce_multishop = {};
-function multishopCheckProductField(checked, id, type)
+var ProductMultishop = new function()
 {
-	checked = !checked;
-	switch (type)
+	var self = this;
+	this.load_tinymce = {};
+
+	this.checkField = function(checked, id, type)
 	{
-		case 'tinymce' :
-			$('#'+id).attr('disabled', checked);
-			if (typeof load_tinymce_multishop[id] == 'undefined')
-				load_tinymce_multishop[id] = checked;
-			else
-			{
-				if (checked)
-					tinyMCE.get(id).hide();
+		checked = !checked;
+		switch (type)
+		{
+			case 'tinymce' :
+				$('#'+id).attr('disabled', checked);
+				if (typeof self.load_tinymce[id] == 'undefined')
+					self.load_tinymce[id] = checked;
 				else
-					tinyMCE.get(id).show();
-			}
-			break;
+				{
+					if (checked)
+						tinyMCE.get(id).hide();
+					else
+						tinyMCE.get(id).show();
+				}
+				break;
 
-		case 'radio' :
-			$('input[name=\''+id+'\']').attr('disabled', checked);
-			break;
+			case 'radio' :
+				$('input[name=\''+id+'\']').attr('disabled', checked);
+				break;
 
-		case 'show_price' :
-			if ($('input[name=\'available_for_order\']').attr('checked'))
-				checked = true;
-			$('input[name=\''+id+'\']').attr('disabled', checked);
-			break;
+			case 'show_price' :
+				if ($('input[name=\'available_for_order\']').attr('checked'))
+					checked = true;
+				$('input[name=\''+id+'\']').attr('disabled', checked);
+				break;
 
-		case 'price' :
-			$('#priceTE').attr('disabled', checked);
-			$('#priceTI').attr('disabled', checked);
-			break;
+			case 'price' :
+				$('#priceTE').attr('disabled', checked);
+				$('#priceTI').attr('disabled', checked);
+				break;
 
-		case 'unit_price' :
-			$('#unit_price').attr('disabled', checked);
-			$('#unity').attr('disabled', checked);
-			break;
+			case 'unit_price' :
+				$('#unit_price').attr('disabled', checked);
+				$('#unity').attr('disabled', checked);
+				break;
 
-		case 'category_box' :
-			$('#categories-treeview input[type=checkbox]').attr('disabled', checked);
-			break;
+			case 'attribute_price_impact' :
+				$('#attribute_price_impact').attr('disabled', checked);
+				$('#attribute_price').attr('disabled', checked);
+				$('#attribute_priceTI').attr('disabled', checked);
+				break;
 
-		default :
-			$('#'+id).attr('disabled', checked);
-			break;
-	}
-}
+			case 'category_box' :
+				$('#categories-treeview input[type=checkbox]').attr('disabled', checked);
+				break;
 
-function multishopCheckAllProductFieldsInformations()
-{
-	multishopCheckProductField($('input[name=\'multishop_check[active]\']').attr('checked'), 'active', 'radio');
-	multishopCheckProductField($('input[name=\'multishop_check[visibility]\']').attr('checked'), 'visibility');
-	multishopCheckProductField($('input[name=\'multishop_check[available_for_order]\']').attr('checked'), 'available_for_order');
-	multishopCheckProductField($('input[name=\'multishop_check[show_price]\']').attr('checked'), 'show_price', 'show_price');
-	multishopCheckProductField($('input[name=\'multishop_check[online_only]\']').attr('checked'), 'online_only');
-	multishopCheckProductField($('input[name=\'multishop_check[condition]\']').attr('checked'), 'condition');
-	$.each(languages, function(k, v)
+			case 'attribute_weight_impact' :
+				$('#attribute_weight_impact').attr('disabled', checked);
+				$('#attribute_weight').attr('disabled', checked);
+				break;
+
+			case 'attribute_unit_impact' :
+				$('#attribute_unit_impact').attr('disabled', checked);
+				$('#attribute_unity').attr('disabled', checked);
+				break;
+
+			default :
+				$('#'+id).attr('disabled', checked);
+				break;
+		}
+	};
+
+	this.checkAllInformations = function()
 	{
-		multishopCheckProductField($('input[name=\'multishop_check[name]['+v.id_lang+']\']').attr('checked'), 'name_'+v.id_lang);
-		multishopCheckProductField($('input[name=\'multishop_check[description_short]['+v.id_lang+']\']').attr('checked'), 'description_short_'+v.id_lang, 'tinymce');
-		multishopCheckProductField($('input[name=\'multishop_check[description]['+v.id_lang+']\']').attr('checked'), 'description_'+v.id_lang, 'tinymce');
-	});
-}
+		ProductMultishop.checkField($('input[name=\'multishop_check[active]\']').attr('checked'), 'active', 'radio');
+		ProductMultishop.checkField($('input[name=\'multishop_check[visibility]\']').attr('checked'), 'visibility');
+		ProductMultishop.checkField($('input[name=\'multishop_check[available_for_order]\']').attr('checked'), 'available_for_order');
+		ProductMultishop.checkField($('input[name=\'multishop_check[show_price]\']').attr('checked'), 'show_price', 'show_price');
+		ProductMultishop.checkField($('input[name=\'multishop_check[online_only]\']').attr('checked'), 'online_only');
+		ProductMultishop.checkField($('input[name=\'multishop_check[condition]\']').attr('checked'), 'condition');
+		$.each(languages, function(k, v)
+		{
+			ProductMultishop.checkField($('input[name=\'multishop_check[name]['+v.id_lang+']\']').attr('checked'), 'name_'+v.id_lang);
+			ProductMultishop.checkField($('input[name=\'multishop_check[description_short]['+v.id_lang+']\']').attr('checked'), 'description_short_'+v.id_lang, 'tinymce');
+			ProductMultishop.checkField($('input[name=\'multishop_check[description]['+v.id_lang+']\']').attr('checked'), 'description_'+v.id_lang, 'tinymce');
+		});
+	};
 
-function multishopCheckAllProductFieldsPrice(checked)
-{
-	multishopCheckProductField($('input[name=\'multishop_check[wholesale_price]\']').attr('checked'), 'wholesale_price');
-	multishopCheckProductField($('input[name=\'multishop_check[price]\']').attr('checked'), 'price', 'price');
-	multishopCheckProductField($('input[name=\'multishop_check[id_tax_rules_group]\']').attr('checked'), 'id_tax_rules_group');
-	multishopCheckProductField($('input[name=\'multishop_check[unit_price]\']').attr('checked'), 'unit_price', 'unit_price');
-	multishopCheckProductField($('input[name=\'multishop_check[on_sale]\']').attr('checked'), 'on_sale');
-}
-
-function multishopCheckAllProductFieldsSeo(checked)
-{
-	$.each(languages, function(k, v)
+	this.checkAllPrice = function()
 	{
-		multishopCheckProductField($('input[name=\'multishop_check[meta_title]['+v.id_lang+']\']').attr('checked'), 'meta_title_'+v.id_lang);
-		multishopCheckProductField($('input[name=\'multishop_check[meta_description]['+v.id_lang+']\']').attr('checked'), 'meta_description_'+v.id_lang);
-		multishopCheckProductField($('input[name=\'multishop_check[meta_keywords]['+v.id_lang+']\']').attr('checked'), 'meta_keywords_'+v.id_lang);
-		multishopCheckProductField($('input[name=\'multishop_check[link_rewrite]['+v.id_lang+']\']').attr('checked'), 'link_rewrite_'+v.id_lang);
-	});
-}
+		ProductMultishop.checkField($('input[name=\'multishop_check[wholesale_price]\']').attr('checked'), 'wholesale_price');
+		ProductMultishop.checkField($('input[name=\'multishop_check[price]\']').attr('checked'), 'price', 'price');
+		ProductMultishop.checkField($('input[name=\'multishop_check[id_tax_rules_group]\']').attr('checked'), 'id_tax_rules_group');
+		ProductMultishop.checkField($('input[name=\'multishop_check[unit_price]\']').attr('checked'), 'unit_price', 'unit_price');
+		ProductMultishop.checkField($('input[name=\'multishop_check[on_sale]\']').attr('checked'), 'on_sale');
+		ProductMultishop.checkField($('input[name=\'multishop_check[on_sale]\']').attr('checked'), 'ecotax');
+	};
 
-function multishopCheckAllProductFieldsAssociations(checked)
-{
-	multishopCheckProductField($('input[name=\'multishop_check[id_category_default]\']').attr('checked'), 'id_category_default');
-	multishopCheckProductField($('input[name=\'multishop_check[category_box]\']').attr('checked'), 'categories-treeview', 'category_box');
-}
+	this.checkAllSeo = function()
+	{
+		$.each(languages, function(k, v)
+		{
+			ProductMultishop.checkField($('input[name=\'multishop_check[meta_title]['+v.id_lang+']\']').attr('checked'), 'meta_title_'+v.id_lang);
+			ProductMultishop.checkField($('input[name=\'multishop_check[meta_description]['+v.id_lang+']\']').attr('checked'), 'meta_description_'+v.id_lang);
+			ProductMultishop.checkField($('input[name=\'multishop_check[meta_keywords]['+v.id_lang+']\']').attr('checked'), 'meta_keywords_'+v.id_lang);
+			ProductMultishop.checkField($('input[name=\'multishop_check[link_rewrite]['+v.id_lang+']\']').attr('checked'), 'link_rewrite_'+v.id_lang);
+		});
+	};
+
+	this.checkAllAssociations = function()
+	{
+		ProductMultishop.checkField($('input[name=\'multishop_check[id_category_default]\']').attr('checked'), 'id_category_default');
+		ProductMultishop.checkField($('input[name=\'multishop_check[id_category_default]\']').attr('checked'), 'categories-treeview', 'category_box');
+	};
+
+	this.checkAllCombinations = function()
+	{
+		ProductMultishop.checkField($('input[name=\'multishop_check[attribute_wholesale_price]\']').attr('checked'), 'attribute_wholesale_price');
+		ProductMultishop.checkField($('input[name=\'multishop_check[attribute_price_impact]\']').attr('checked'), 'attribute_price_impact', 'attribute_price_impact');
+		ProductMultishop.checkField($('input[name=\'multishop_check[attribute_weight_impact]\']').attr('checked'), 'attribute_weight_impact', 'attribute_weight_impact');
+		ProductMultishop.checkField($('input[name=\'multishop_check[attribute_unit_impact]\']').attr('checked'), 'attribute_unit_impact', 'attribute_unit_impact');
+		ProductMultishop.checkField($('input[name=\'multishop_check[attribute_ecotax]\']').attr('checked'), 'attribute_ecotax');
+		ProductMultishop.checkField($('input[name=\'multishop_check[attribute_minimal_quantity]\']').attr('checked'), 'attribute_minimal_quantity');
+		ProductMultishop.checkField($('input[name=\'multishop_check[available_date_attribute]\']').attr('checked'), 'available_date_attribute');
+		ProductMultishop.checkField($('input[name=\'multishop_check[attribute_default]\']').attr('checked'), 'attribute_default');
+	};
+};
 
 var tabs_manager = new ProductTabsManager();
 tabs_manager.setTabs(product_tabs);