diff --git a/classes/Category.php b/classes/Category.php
index 8dc4f043a..3ccc08776 100644
--- a/classes/Category.php
+++ b/classes/Category.php
@@ -47,6 +47,9 @@ class CategoryCore extends ObjectModel
 	/** @var integer Parent category ID */
 	public $id_parent;
 
+	/** @var integer default Category id */
+	public $id_category_default;
+
 	/** @var integer Parents number */
 	public $level_depth;
 
@@ -95,6 +98,7 @@ class CategoryCore extends ObjectModel
 			'level_depth' => 		array('type' => self::TYPE_INT, 'validate' => 'isUnsignedInt'),
 			'active' => 			array('type' => self::TYPE_BOOL, 'validate' => 'isBool', 'required' => true),
 			'id_parent' => 			array('type' => self::TYPE_INT, 'validate' => 'isUnsignedInt'),
+			'id_shop_default' => 	array('type' => self::TYPE_INT, 'validate' => 'isUnsignedId'),
 			'is_root_category' => 	array('type' => self::TYPE_BOOL, 'validate' => 'isBool'),
 			'position' => 			array('type' => self::TYPE_INT),
 			'date_add' => 			array('type' => self::TYPE_DATE, 'validate' => 'isDate'),
diff --git a/classes/ObjectModel.php b/classes/ObjectModel.php
index d7f04093d..3c85d68dc 100644
--- a/classes/ObjectModel.php
+++ b/classes/ObjectModel.php
@@ -449,9 +449,19 @@ abstract class ObjectModelCore
 		if ($autodate && property_exists($this, 'date_upd'))
 			$this->date_upd = date('Y-m-d H:i:s');
 
+			
+		if (Shop::isTableAssociated($this->def['table']))
+		{
+			$id_shop_list = Shop::getContextListShopID();
+			if (count($this->id_shop_list) > 0)
+				$id_shop_list = $this->id_shop_list;
+		}
+		
 		// Database insertion
 		if (isset($this->id))
 			unset($this->id);
+		if (Shop::checkIdShopDefault($this->def['table']))
+			$this->id_shop_default = min($id_shop_list);
 		if (!$result = ObjectModel::$db->insert($this->def['table'], $this->getFields(), $null_values))
 			return false;
 
@@ -461,10 +471,6 @@ abstract class ObjectModelCore
 		// Database insertion for multishop fields related to the object
 		if (Shop::isTableAssociated($this->def['table']))
 		{
-			$id_shop_list = Shop::getContextListShopID();
-			if (count($this->id_shop_list) > 0)
-				$id_shop_list = $this->id_shop_list;	
-				
 			$fields = $this->getFieldsShop();
 			$fields[$this->def['primary']] = (int)$this->id;
 
@@ -534,7 +540,13 @@ abstract class ObjectModelCore
 		// Automatically fill dates
 		if (array_key_exists('date_upd', $this))
 			$this->date_upd = date('Y-m-d H:i:s');
+			
+		$id_shop_list = Shop::getContextListShopID();
+		if (count($this->id_shop_list) > 0)
+			$id_shop_list = $this->id_shop_list;
 
+		if (Shop::checkIdShopDefault($this->def['table']))
+			$this->id_shop_default = min($id_shop_list);
 		// Database update
 		if (!$result = ObjectModel::$db->update($this->def['table'], $this->getFields(), '`'.pSQL($this->def['primary']).'` = '.(int)$this->id, 0, $null_values))
 			return false;
@@ -555,9 +567,6 @@ abstract class ObjectModelCore
 			else
 				$all_fields = $fields;
 
-			$id_shop_list = Shop::getContextListShopID();
-			if (count($this->id_shop_list) > 0)
-				$id_shop_list = $this->id_shop_list;
 
 			foreach ($id_shop_list as $id_shop)
 			{
diff --git a/classes/Product.php b/classes/Product.php
index 6f3800e31..5a8c7df67 100644
--- a/classes/Product.php
+++ b/classes/Product.php
@@ -51,6 +51,9 @@ class ProductCore extends ObjectModel
 	/** @var integer default Category id */
 	public $id_category_default;
 
+	/** @var integer default Shop id */
+	public $id_shop_default;
+
 	/** @var string Manufacturer name */
 	public $manufacturer_name;
 
@@ -237,6 +240,7 @@ class ProductCore extends ObjectModel
 		'multilang_shop' => true,
 		'fields' => array(
 			// Classic fields
+			'id_shop_default' => 			array('type' => self::TYPE_INT, 'validate' => 'isUnsignedId'),
 			'id_manufacturer' => 			array('type' => self::TYPE_INT, 'validate' => 'isUnsignedId'),
 			'id_supplier' => 				array('type' => self::TYPE_INT, 'validate' => 'isUnsignedId'),
 			'reference' => 					array('type' => self::TYPE_STRING, 'validate' => 'isReference', 'size' => 32),
@@ -2451,7 +2455,7 @@ class ProductCore extends ObjectModel
 					LIMIT 1
 				) as default_on');
 				$sql->leftJoin('product_attribute', 'pa', 'pa.`id_product` = '.(int)$id_product);
-				$sql->join(Shop::addSqlAssociation('product_attribute', 'pa', false));
+				$sql->join(Shop::addSqlAssociation('product_attribute', 'pa', false, 'product_attribute_shop.id_shop = p.id_shop_default'));
 			}
 			$res = Db::getInstance(_PS_USE_SQL_SLAVE_)->executeS($sql);
 			
diff --git a/classes/controller/AdminController.php b/classes/controller/AdminController.php
index fafcb5276..ffb192110 100644
--- a/classes/controller/AdminController.php
+++ b/classes/controller/AdminController.php
@@ -109,6 +109,9 @@ class AdminControllerCore extends Controller
 
 	protected $shopLink;
 
+	/** @var string SQL query */
+	protected $_listsql = '';
+
 	/** @var array Cache for query results */
 	protected $_list = array();
 
@@ -248,6 +251,7 @@ class AdminControllerCore extends Controller
 	public $controller_name;
 
 	public $multishop_context = -1;
+	public $multishop_context_group = true;
 
 	/**
 	 * Current breadcrumb position as an array of tab names
@@ -1927,6 +1931,9 @@ class AdminControllerCore extends Controller
 	 */
 	public function getList($id_lang, $order_by = null, $order_way = null, $start = 0, $limit = null, $id_lang_shop = false)
 	{
+		if (!empty($this->_listsql))
+			return;
+	
 		/* Manage default params values */
 		$use_limit = true;
 		if ($limit === false)
@@ -1997,22 +2004,19 @@ class AdminControllerCore extends Controller
 			$where_shop = Shop::addSqlRestriction($this->shopShareDatas, 'a', $this->shopLinkType);
 		}
 
-		$filter_shop = '';
 		if ($this->multishop_context && Shop::isTableAssociated($this->table) && !empty($this->className))
 		{
 			if (Shop::getContext() != Shop::CONTEXT_ALL || Shop::isTableAssociated($this->table) || !$this->context->employee->isSuperAdmin())
 			{
-				$idenfier_shop = Shop::getContextListShopID();
-				if (!$this->_group)
-					$this->_group = ' GROUP BY a.'.pSQL($this->identifier);
-				elseif (!preg_match('#(\s|,)\s*a\.`?'.pSQL($this->identifier).'`?(\s|,|$)#', $this->_group))
-					$this->_group .= ', a.'.pSQL($this->identifier);
-
+				$identifier_shop = Shop::getContextListShopID();
 				$test_join = !preg_match('#`?'.preg_quote(_DB_PREFIX_.$this->table.'_shop').'`? *sa#', $this->_join);
 				if (Shop::isFeatureActive() && $test_join)
 				{
-					$filter_shop = ' JOIN `'._DB_PREFIX_.$this->table.'_shop` sa ';
-					$filter_shop .= 'ON (sa.'.$this->identifier.' = a.'.$this->identifier.' AND sa.id_shop IN ('.implode(', ', $idenfier_shop).'))';
+					$this->_where .= ' AND a.'.$this->identifier.' IN (
+						SELECT sa.'.$this->identifier.'
+						FROM `'._DB_PREFIX_.$this->table.'_shop` sa
+						WHERE sa.id_shop IN ('.implode(', ', $identifier_shop).')
+					)';
 				}
 			}
 		}
@@ -2021,13 +2025,14 @@ class AdminControllerCore extends Controller
 		$lang_join = '';
 		if ($this->lang)
 		{
-			$lang_join = 'LEFT JOIN `'._DB_PREFIX_.$this->table.'_lang` b ON (b.`'.$this->identifier.'` = a.`'.$this->identifier.'`';
-			$lang_join .= ' AND b.`id_lang` = '.(int)$id_lang;
+			$lang_join = 'LEFT JOIN `'._DB_PREFIX_.$this->table.'_lang` b ON (b.`'.$this->identifier.'` = a.`'.$this->identifier.'` AND b.`id_lang` = '.(int)$id_lang;
 			if ($id_lang_shop)
+			{
 				if (Shop::getContext() == Shop::CONTEXT_SHOP)
-					$lang_join .= ' AND b.`id_shop`='.(int)$id_lang_shop;
+					$lang_join .= ' AND b.`id_shop` = '.(int)$id_lang_shop;
 				else
-					$lang_join .= ' AND b.`id_shop` IN ('.implode(',', array_map('intval', Shop::getContextListShopID())).')';
+					$lang_join .= ' AND b.`id_shop` = a.id_shop_default';
+			}
 			$lang_join .= ')';
 		}
 
@@ -2047,23 +2052,23 @@ class AdminControllerCore extends Controller
 			$order_by = pSQL($order_by[0]).'.`'.pSQL($order_by[1]).'`';
 		}
 
-		$sql = 'SELECT SQL_CALC_FOUND_ROWS
-			'.($this->_tmpTableFilter ? ' * FROM (SELECT ' : '').'
-			'.($this->lang ? 'b.*, ' : '').'a.*'.(isset($this->_select) ? ', '.$this->_select.' ' : '').$select_shop.'
-			FROM `'._DB_PREFIX_.$sql_table.'` a
-			'.$filter_shop.'
-			'.$lang_join.'
-			'.(isset($this->_join) ? $this->_join.' ' : '').'
-			'.$join_shop.'
-			WHERE 1 '.(isset($this->_where) ? $this->_where.' ' : '').($this->deleted ? 'AND a.`deleted` = 0 ' : '').
-			(isset($this->_filter) ? $this->_filter : '').$where_shop.'
-			'.(isset($this->_group) ? $this->_group.' ' : '').'
-			'.$having_clause.'
-			ORDER BY '.(($order_by == $this->identifier) ? 'a.' : '').pSQL($order_by).' '.pSQL($order_way).
-			($this->_tmpTableFilter ? ') tmpTable WHERE 1'.$this->_tmpTableFilter : '').
-			(($use_limit === true) ? ' LIMIT '.(int)$start.','.(int)$limit : '');
+		$this->_listsql = '
+		SELECT SQL_CALC_FOUND_ROWS
+		'.($this->_tmpTableFilter ? ' * FROM (SELECT ' : '').'
+		'.($this->lang ? 'b.*, ' : '').'a.*'.(isset($this->_select) ? ', '.$this->_select.' ' : '').$select_shop.'
+		FROM `'._DB_PREFIX_.$sql_table.'` a
+		'.$lang_join.'
+		'.(isset($this->_join) ? $this->_join.' ' : '').'
+		'.$join_shop.'
+		WHERE 1 '.(isset($this->_where) ? $this->_where.' ' : '').($this->deleted ? 'AND a.`deleted` = 0 ' : '').
+		(isset($this->_filter) ? $this->_filter : '').$where_shop.'
+		'.(isset($this->_group) ? $this->_group.' ' : '').'
+		'.$having_clause.'
+		ORDER BY '.(($order_by == $this->identifier) ? 'a.' : '').pSQL($order_by).' '.pSQL($order_way).
+		($this->_tmpTableFilter ? ') tmpTable WHERE 1'.$this->_tmpTableFilter : '').
+		(($use_limit === true) ? ' LIMIT '.(int)$start.','.(int)$limit : '');
 
-		$this->_list = Db::getInstance()->executeS($sql);
+		$this->_list = Db::getInstance()->executeS($this->_listsql);
 		$this->_listTotal = Db::getInstance()->getValue('SELECT FOUND_ROWS() AS `'._DB_PREFIX_.$this->table.'`');
 	}
 
diff --git a/classes/helper/Helper.php b/classes/helper/Helper.php
index 0fa7e758c..0693a4c9a 100755
--- a/classes/helper/Helper.php
+++ b/classes/helper/Helper.php
@@ -361,9 +361,10 @@ class HelperCore
 		$context = Context::getContext();
 
 		// Get default value
-		if (Shop::getContext() == Shop::CONTEXT_ALL)
+		$shop_context = Shop::getContext();
+		if ($shop_context == Shop::CONTEXT_ALL || ($context->controller->multishop_context_group == false && $shop_context == Shop::CONTEXT_GROUP))
 			$value = '';
-		else if (Shop::getContext() == Shop::CONTEXT_GROUP)
+		else if ($shop_context == Shop::CONTEXT_GROUP)
 			$value = 'g-'.Shop::getContextShopGroupID();
 		else
 			$value = 's-'.Shop::getContextShopID();
@@ -376,9 +377,9 @@ class HelperCore
 		foreach ($tree as $gID => $group_data)
 		{
 			if ((!isset($context->controller->multishop_context) || $context->controller->multishop_context & Shop::CONTEXT_GROUP))
-				$html .= '<option class="group" value="g-'.$gID.'" '.(($value == 'g-'.$gID) ? 'selected="selected"' : '').'>'.Translate::getAdminTranslation('Group:').' '.htmlspecialchars($group_data['name']).'</option>';
+				$html .= '<option class="group" value="g-'.$gID.'" '.(($value == 'g-'.$gID) ? 'selected="selected"' : '').' '.($context->controller->multishop_context_group == false ? 'disabled="disabled"' : '').'>'.Translate::getAdminTranslation('Group:').' '.htmlspecialchars($group_data['name']).'</option>';
 			else
-				$html .= '<optgroup class="group" label="'.Translate::getAdminTranslation('Group:').' '.htmlspecialchars($group_data['name']).'">';
+				$html .= '<optgroup class="group" label="'.Translate::getAdminTranslation('Group:').' '.htmlspecialchars($group_data['name']).'" '.($context->controller->multishop_context_group == false ? 'disabled="disabled"' : '').'>';
 
 			if (!isset($context->controller->multishop_context) || $context->controller->multishop_context & Shop::CONTEXT_SHOP)
 				foreach ($group_data['shops'] as $sID => $shopData)
diff --git a/classes/shop/Shop.php b/classes/shop/Shop.php
index 2229f878e..8b30c4522 100644
--- a/classes/shop/Shop.php
+++ b/classes/shop/Shop.php
@@ -86,6 +86,7 @@ class ShopCore extends ObjectModel
 	protected static $shops;
 
 	protected static $asso_tables = array();
+	protected static $id_shop_default_tables = array();
 	protected static $initialized = false;
 
 	protected $webserviceParameters = array(
@@ -139,6 +140,7 @@ class ShopCore extends ObjectModel
 	 */
 	protected static function init()
 	{
+		Shop::$id_shop_default_tables = array('product', 'category');
 		Shop::$asso_tables = array(
 			'carrier' => array('type' => 'shop'),
 			'carrier_lang' => array('type' => 'fk_shop'),
@@ -503,6 +505,18 @@ class ShopCore extends ObjectModel
 			Shop::init();
 		return (isset(Shop::$asso_tables[$table]) ? Shop::$asso_tables[$table] : false);
 	}
+	
+	/**
+	 * check if the table has an id_shop_default
+	 *
+	 * @return boolean
+	 */
+	public static function checkIdShopDefault($table)
+	{
+		if (!Shop::$initialized)
+			Shop::init();
+		return in_array($table, self::$id_shop_default_tables);
+	}
 
 	/**
 	 * Get list of associated tables to shop
@@ -888,9 +902,12 @@ class ShopCore extends ObjectModel
 			return;
 
 		$sql = (($inner_join) ? ' INNER' : ' LEFT').' JOIN '._DB_PREFIX_.$table.'_shop '.$table_alias.'
-		ON '.$table_alias.'.id_'.$table.' = '.$alias.'.id_'.$table.'
-		AND '.$table_alias.'.id_shop IN ('.implode(', ', Shop::getContextListShopID()).')
-		'.(($on) ? ' AND '.$on : '');
+		ON ('.$table_alias.'.id_'.$table.' = '.$alias.'.id_'.$table;
+		if ((int)self::$context_id_shop)
+			$sql .= ' AND '.$table_alias.'.id_shop = '.(int)self::$context_id_shop;
+		elseif (Shop::checkIdShopDefault($table))
+			$sql .= ' AND '.$table_alias.'.id_shop = '.$alias.'.id_shop_default';
+		$sql .= (($on) ? ' AND '.$on : '').')';
 		return $sql;
 	}
 
diff --git a/controllers/admin/AdminCategoriesController.php b/controllers/admin/AdminCategoriesController.php
index 43c14e03c..11ad2b8e9 100644
--- a/controllers/admin/AdminCategoriesController.php
+++ b/controllers/admin/AdminCategoriesController.php
@@ -163,12 +163,17 @@ class AdminCategoriesControllerCore extends AdminController
 			$id_parent = $this->context->shop->id_category;
 
 		$this->_filter .= ' AND `id_parent` = '.(int)$id_parent.' ';
-		$this->_select = 'category_shop.`position` ';
-		$this->_join = Shop::addSqlAssociation('category', 'a');
-		$this->_group = 'GROUP BY a.id_category';
+		if (Shop::isFeatureActive())
+		{
+			if (Shop::getContext() == Shop::CONTEXT_SHOP)
+				$this->_join .= ' LEFT JOIN `'._DB_PREFIX_.'category_shop` sa ON (a.`id_category` = sa.`id_category` AND sa.id_shop = '.(int)$this->context->shop->id.') ';
+			else
+				$this->_join .= ' LEFT JOIN `'._DB_PREFIX_.'category_shop` sa ON (a.`id_category` = sa.`id_category` AND sa.id_shop = a.id_shop_default) ';
+		}
+
 		// we add restriction for shop
 		if (Shop::getContext() == Shop::CONTEXT_SHOP && $is_multishop)
-			$this->_where = ' AND category_shop.`id_shop` = '.(int)Context::getContext()->shop->id;
+			$this->_where = ' AND sa.`id_shop` = '.(int)Context::getContext()->shop->id;
 
 		$categories_tree = $this->_category->getParentsCategories();
 		if (empty($categories_tree)
@@ -196,7 +201,7 @@ class AdminCategoriesControllerCore extends AdminController
 
 	public function getList($id_lang, $order_by = null, $order_way = null, $start = 0, $limit = null, $id_lang_shop = false)
 	{
-		parent::getList($id_lang, 'category_shop.position', $order_way, $start, $limit, Context::getContext()->shop->id);
+		parent::getList($id_lang, 'sa.position', $order_way, $start, $limit, Context::getContext()->shop->id);
 		// Check each row to see if there are combinations and get the correct action in consequence
 
 		$nb_items = count($this->_list);
@@ -499,6 +504,9 @@ class AdminCategoriesControllerCore extends AdminController
 	
 	public function postProcess()
 	{
+		if (!in_array($this->display, array('edit', 'add')))
+			$this->multishop_context_group = false;
+
 		if (Tools::isSubmit('forcedeleteImage'))
 		{
 			$this->processForceDeleteImage();
diff --git a/controllers/admin/AdminProductsController.php b/controllers/admin/AdminProductsController.php
index 80d01c419..53ce4ead7 100644
--- a/controllers/admin/AdminProductsController.php
+++ b/controllers/admin/AdminProductsController.php
@@ -78,6 +78,9 @@ class AdminProductsControllerCore extends AdminController
 		$this->lang = true;
 		$this->bulk_actions = array('delete' => array('text' => $this->l('Delete selected'), 'confirm' => $this->l('Delete selected items?')));
 
+		if (!Tools::getValue('id_product'))
+			$this->multishop_context_group = false;
+
 		parent::__construct();
 
 		$this->imageType = 'jpg';
@@ -85,75 +88,82 @@ class AdminProductsControllerCore extends AdminController
 		$this->max_file_size = (int)(Configuration::get('PS_LIMIT_UPLOAD_FILE_VALUE') * 1000000);
 		$this->max_image_size = (int)Configuration::get('PS_PRODUCT_PICTURE_MAX_SIZE');
 
-		$this->fields_list = array(
-			'id_product' => array(
-				'title' => $this->l('ID'),
-				'align' => 'center',
-				'width' => 20
-			),
-			'image' => array(
-				'title' => $this->l('Photo'),
-				'align' => 'center',
-				'image' => 'p',
-				'width' => 70,
-				'orderby' => false,
-				'filter' => false,
-				'search' => false
-			),
-			'name' => array(
-				'title' => $this->l('Name'),
-				'filter_key' => 'b!name'
-			),
-			'reference' => array(
-				'title' => $this->l('Reference'),
-				'align' => 'left',
-				'width' => 80
-			),
-			'name_category' => array(
+		$this->fields_list = array();
+		$this->fields_list['id_product'] = array(
+			'title' => $this->l('ID'),
+			'align' => 'center',
+			'width' => 20
+		);
+		$this->fields_list['image'] = array(
+			'title' => $this->l('Photo'),
+			'align' => 'center',
+			'image' => 'p',
+			'width' => 70,
+			'orderby' => false,
+			'filter' => false,
+			'search' => false
+		);
+		$this->fields_list['name'] = array(
+			'title' => $this->l('Name'),
+			'filter_key' => 'b!name'
+		);
+		$this->fields_list['reference'] = array(
+			'title' => $this->l('Reference'),
+			'align' => 'left',
+			'width' => 80
+		);
+		if (Shop::isFeatureActive() && Shop::getContext() != Shop::CONTEXT_SHOP)
+			$this->fields_list['shopname'] = array(
+				'title' => $this->l('Default Shop'),
+				'width' => 230,
+				'filter_key' => 'shop!name',
+			);
+		else
+			$this->fields_list['name_category'] = array(
 				'title' => $this->l('Category'),
 				'width' => 230,
 				'filter_key' => 'cl!name',
-			),
-			'price' => array(
-				'title' => $this->l('Base price'),
-				'width' => 90,
-				'type' => 'price',
-				'align' => 'right',
-				'filter_key' => 'a!price'
-			),
-			'price_final' => array(
-				'title' => $this->l('Final price'),
-				'width' => 90,
-				'type' => 'price',
-				'align' => 'right',
-				'havingFilter' => true,
-				'orderby' => false
-			),
-			'sav_quantity' => array(
-				'title' => $this->l('Quantity'),
-				'width' => 90,
-				'align' => 'right',
-				'filter_key' => 'sav!quantity',
-				'orderby' => true,
-				'hint' => $this->l('This is the quantity available in the current shop/group'),
-			),
-			'active' => array(
-				'title' => $this->l('Displayed'),
-				'width' => 70,
-				'active' => 'status',
-				'filter_key' => 'a!active',
-				'align' => 'center',
-				'type' => 'bool',
-				'orderby' => false
-			),
-			'position' => array(
-				'title' => $this->l('Position'),
-				'width' => 70,
-				'filter_key' => 'cp!position',
-				'align' => 'center',
-				'position' => 'position'
-			)
+			);
+		$this->fields_list['price'] = array(
+			'title' => $this->l('Base price'),
+			'width' => 90,
+			'type' => 'price',
+			'align' => 'right',
+			'filter_key' => 'a!price'
 		);
+		$this->fields_list['price_final'] = array(
+			'title' => $this->l('Final price'),
+			'width' => 90,
+			'type' => 'price',
+			'align' => 'right',
+			'havingFilter' => true,
+			'orderby' => false
+		);
+		$this->fields_list['sav_quantity'] = array(
+			'title' => $this->l('Quantity'),
+			'width' => 90,
+			'align' => 'right',
+			'filter_key' => 'sav!quantity',
+			'orderby' => true,
+			'hint' => $this->l('This is the quantity available in the current shop/group'),
+		);
+		$this->fields_list['active'] = array(
+			'title' => $this->l('Displayed'),
+			'width' => 70,
+			'active' => 'status',
+			'filter_key' => 'a!active',
+			'align' => 'center',
+			'type' => 'bool',
+			'orderby' => false
+		);
+		$this->fields_list['position'] = array(
+			'title' => $this->l('Position'),
+			'width' => 70,
+			'filter_key' => 'cp!position',
+			'align' => 'center',
+			'position' => 'position'
+		);
+
 
 		// @since 1.5 : translations for tabs
 		$this->available_tabs_lang = array (
@@ -195,22 +205,39 @@ class AdminProductsControllerCore extends AdminController
 			$this->_category = new Category((int)$id_category);
 		else
 			$this->_category = new Category();
-
-		$alias = Shop::isFeatureActive() ? 'sa' : 'a';
-		$this->_join =
-			'LEFT JOIN `'._DB_PREFIX_.'category_lang` cl ON ('.$alias.'.`id_category_default` = cl.`id_category` AND b.`id_lang` = cl.`id_lang`)
-			LEFT JOIN `'._DB_PREFIX_.'image` i ON (i.`id_product` = a.`id_product` AND i.`cover` = 1)
-			LEFT JOIN `'._DB_PREFIX_.'category_product` cp ON (cp.`id_product` = a.`id_product`)
-			LEFT JOIN `'._DB_PREFIX_.'tax_rule` tr ON ('.$alias.'.`id_tax_rules_group` = tr.`id_tax_rules_group`
-				AND tr.`id_country` = '.(int)$this->context->country->id.' AND tr.`id_state` = 0)
-			LEFT JOIN `'._DB_PREFIX_.'tax` t ON (t.`id_tax` = tr.`id_tax`)
-			LEFT JOIN `'._DB_PREFIX_.'stock_available` sav ON (sav.`id_product` = a.`id_product` AND sav.`id_product_attribute` = 0
-			'.StockAvailable::addSqlShopRestriction(null, null, 'sav').')';
-		// if no category selected, display all products
+			
+		$join_category = false;
 		if (Validate::isLoadedObject($this->_category) && empty($this->_filter))
-			$this->_filter = 'AND cp.`id_category` = '.(int)$this->_category->id;
+			$join_category = true;
 
-		$this->_select = 'cl.name `name_category`, cp.`position`, i.`id_image`, '.$alias.'.`price`, ('.$alias.'.`price` * ((100 + (t.`rate`))/100)) AS price_final, sav.`quantity` as sav_quantity, '.$alias.'.`active`';
+		if (Shop::isFeatureActive())
+		{
+			$alias = 'sa';
+			if (Shop::getContext() == Shop::CONTEXT_SHOP)
+				$this->_join .= ' LEFT JOIN `'._DB_PREFIX_.'product_shop` sa ON (a.`id_product` = sa.`id_product` AND sa.id_shop = '.(int)$this->context->shop->id.')
+				LEFT JOIN `'._DB_PREFIX_.'category_lang` cl ON ('.$alias.'.`id_category_default` = cl.`id_category` AND b.`id_lang` = cl.`id_lang` AND cl.id_shop = '.(int)$this->context->shop->id.')
+				LEFT JOIN `'._DB_PREFIX_.'shop` shop ON (shop.id_shop = '.(int)$this->context->shop->id.') ';
+			else
+				$this->_join .= ' LEFT JOIN `'._DB_PREFIX_.'product_shop` sa ON (a.`id_product` = sa.`id_product` AND sa.id_shop = a.id_shop_default)
+				LEFT JOIN `'._DB_PREFIX_.'category_lang` cl ON ('.$alias.'.`id_category_default` = cl.`id_category` AND b.`id_lang` = cl.`id_lang` AND cl.id_shop = a.id_shop_default)
+				LEFT JOIN `'._DB_PREFIX_.'shop` shop ON (shop.id_shop = a.id_shop_default) ';
+			$this->_select .= 'shop.name as shopname, ';
+		}
+		else
+		{
+			$alias = 'a';
+			$this->_join .= 'LEFT JOIN `'._DB_PREFIX_.'category_lang` cl ON ('.$alias.'.`id_category_default` = cl.`id_category` AND b.`id_lang` = cl.`id_lang` AND cl.id_shop = 1)';
+		}
+
+		$this->_join .= '
+		LEFT JOIN `'._DB_PREFIX_.'image` i ON (i.`id_product` = a.`id_product` AND i.`cover` = 1)
+		'.($join_category ? 'LEFT JOIN `'._DB_PREFIX_.'category_product` cp ON (cp.`id_product` = a.`id_product` AND cp.`id_category` = '.(int)$this->_category->id.')' : '').'
+		LEFT JOIN `'._DB_PREFIX_.'tax_rule` tr ON ('.$alias.'.`id_tax_rules_group` = tr.`id_tax_rules_group` AND tr.`id_country` = '.(int)$this->context->country->id.' AND tr.`id_state` = 0)
+		LEFT JOIN `'._DB_PREFIX_.'tax` t ON (t.`id_tax` = tr.`id_tax`)
+		LEFT JOIN `'._DB_PREFIX_.'stock_available` sav ON (sav.`id_product` = a.`id_product` AND sav.`id_product_attribute` = 0
+		'.StockAvailable::addSqlShopRestriction(null, null, 'sav').') ';
+
+		$this->_select .= 'cl.name `name_category` '.($join_category ? ', cp.`position`' : '').', i.`id_image`, '.$alias.'.`price`, ('.$alias.'.`price` * ((100 + (t.`rate`))/100)) AS price_final, sav.`quantity` as sav_quantity, '.$alias.'.`active`';
 		
 	}
 	protected function _cleanMetaKeywords($keywords)
diff --git a/install-dev/data/db_structure.sql b/install-dev/data/db_structure.sql
index 8754b5e18..3abfd8e33 100644
--- a/install-dev/data/db_structure.sql
+++ b/install-dev/data/db_structure.sql
@@ -310,6 +310,7 @@ CREATE TABLE `PREFIX_cart_product` (
 CREATE TABLE `PREFIX_category` (
   `id_category` int(10) unsigned NOT NULL auto_increment,
   `id_parent` int(10) unsigned NOT NULL,
+  `id_shop_default` int(10) unsigned NOT NULL default 1,
   `level_depth` tinyint(3) unsigned NOT NULL default '0',
   `nleft` int(10) unsigned NOT NULL default '0',
   `nright` int(10) unsigned NOT NULL default '0',
@@ -1343,6 +1344,7 @@ CREATE TABLE `PREFIX_product` (
   `id_supplier` int(10) unsigned default NULL,
   `id_manufacturer` int(10) unsigned default NULL,
   `id_category_default` int(10) unsigned default NULL,
+  `id_shop_default` int(10) unsigned NOT NULL default 1,
   `id_tax_rules_group` INT(11) UNSIGNED NOT NULL,
   `on_sale` tinyint(1) unsigned NOT NULL default '0',
   `online_only` tinyint(1) unsigned NOT NULL default '0',
@@ -2403,7 +2405,6 @@ CREATE TABLE `PREFIX_category_shop` (
   `id_shop` int(11) NOT NULL,
   `position` int(10) unsigned NOT NULL default '0',
   PRIMARY KEY (`id_category`, `id_shop`),
-  UNIQUE KEY `id_category_shop` (`id_category`,`id_shop`)
 ) ENGINE=ENGINE_TYPE  DEFAULT CHARSET=utf8;
 
 CREATE TABLE `PREFIX_module_preference` (
diff --git a/install-dev/upgrade/sql/1.5.0.16.sql b/install-dev/upgrade/sql/1.5.0.16.sql
index ffe327708..19c7b3c71 100644
--- a/install-dev/upgrade/sql/1.5.0.16.sql
+++ b/install-dev/upgrade/sql/1.5.0.16.sql
@@ -14,3 +14,8 @@ UPDATE `PREFIX_employee` SET bo_theme = 'default';
 
 ALTER TABLE `PREFIX_tax_rule` ADD INDEX `category_getproducts` ( `id_tax_rules_group` , `id_country` , `id_state` , `zipcode_from` );
 ALTER TABLE `PREFIX_stock_available` ADD INDEX `product_sqlstock` ( `id_product` , `id_product_attribute` , `id_shop` );
+
+ALTER TABLE `PREFIX_product` ADD `id_shop_default` int(10) unsigned NOT NULL default 1 AFTER `id_category_default`;
+UPDATE `PREFIX_product` p SET `id_shop_default` = IFNULL((SELECT MIN(id_shop) FROM `PREFIX_product_shop` ps WHERE ps.`id_product` = p.`id_product`), 1);
+ALTER TABLE `PREFIX_category` ADD `id_shop_default` int(10) unsigned NOT NULL default 1 AFTER `id_parent`;
+UPDATE `PREFIX_category` c SET `id_shop_default` = IFNULL((SELECT MIN(id_shop) FROM `PREFIX_category_shop` cs WHERE cs.`id_category` = c.`id_category`), 1);