diff --git a/classes/Product.php b/classes/Product.php
index fb71dd729..482678440 100644
--- a/classes/Product.php
+++ b/classes/Product.php
@@ -987,7 +987,7 @@ class ProductCore extends ObjectModel
 		return count($result) > 0;
 	}
 
-	public function productAttributeExists($attributes_list, $current_product_attribute = false, Context $context = null)
+	public function productAttributeExists($attributes_list, $current_product_attribute = false, Context $context = null, $all_shops = false, $return_id = false)
 	{
 		if (!Combination::isFeatureActive())
 			return false;
@@ -998,7 +998,7 @@ class ProductCore extends ObjectModel
 			FROM `'._DB_PREFIX_.'product_attribute` pa
 			JOIN `'._DB_PREFIX_.'product_attribute_shop` pas ON (pas.id_product_attribute = pa.id_product_attribute)
 			LEFT JOIN `'._DB_PREFIX_.'product_attribute_combination` pac ON (pac.`id_product_attribute` = pa.`id_product_attribute`)
-			WHERE pas.id_shop ='.(int)$context->shop->id.' AND pa.`id_product` = '.(int)$this->id
+			WHERE 1 '.(!$all_shops ? ' AND pas.id_shop ='.(int)$context->shop->id : '').' AND pa.`id_product` = '.(int)$this->id
 		);
 
 		/* If something's wrong */
@@ -1017,9 +1017,17 @@ class ProductCore extends ObjectModel
 				$diff = false;
 				for ($i = 0; $diff == false && isset($product_attribute[$i]); $i++)
 					if (!in_array($product_attribute[$i], $attributes_list) || $key == $current_product_attribute)
-						$diff = true;
+					{
+						if ($return_id)
+							return $key;
+						return true;		
+					}
 				if (!$diff)
+				{
+					if ($return_id)
+						return $key;
 					return true;
+				}
 			}
 
 		return false;
diff --git a/controllers/admin/AdminProductsController.php b/controllers/admin/AdminProductsController.php
index 8aebf16b6..e0f06ffa0 100644
--- a/controllers/admin/AdminProductsController.php
+++ b/controllers/admin/AdminProductsController.php
@@ -668,35 +668,31 @@ class AdminProductsControllerCore extends AdminController
 				if (Tools::getValue('attribute_default'))
 					$product->deleteDefaultAttributes();
 				// Change existing one
-				if ($id_product_attribute = (int)Tools::getValue('id_product_attribute'))
+				if (($id_product_attribute = (int)Tools::getValue('id_product_attribute')) || ($id_product_attribute = $product->productAttributeExists(Tools::getValue('attribute_combination_list'), false, null, true, true)))
 				{
 					if ($this->tabAccess['edit'] === '1')
 					{
-						if ($product->productAttributeExists(Tools::getValue('attribute_combination_list'), (int)$id_product_attribute))
-							$this->errors[] = Tools::displayError('This attribute already exists.');
+
+						if ($this->isProductFieldUpdated('available_date_attribute') && !Validate::isDateFormat(Tools::getValue('available_date_attribute')))
+							$this->errors[] = Tools::displayError('Invalid date format.');
 						else
 						{
-							if ($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,
-									$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'),
-									$this->isProductFieldUpdated('attribute_default') ? Tools::getValue('attribute_default') : null,
-									Tools::getValue('attribute_location'),
-									Tools::getValue('attribute_upc'),
-									$this->isProductFieldUpdated('attribute_minimal_quantity') ? Tools::getValue('attribute_minimal_quantity') : null,
-									$this->isProductFieldUpdated('available_date_attribute') ? Tools::getValue('available_date_attribute') : null,
-									false);
-							}
-						}
+							$product->updateAttribute((int)$id_product_attribute,
+								$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'),
+								$this->isProductFieldUpdated('attribute_default') ? Tools::getValue('attribute_default') : null,
+								Tools::getValue('attribute_location'),
+								Tools::getValue('attribute_upc'),
+								$this->isProductFieldUpdated('attribute_minimal_quantity') ? Tools::getValue('attribute_minimal_quantity') : null,
+								$this->isProductFieldUpdated('available_date_attribute') ? Tools::getValue('available_date_attribute') : null,
+								false);
+						}						
 					}
 					else
 						$this->errors[] = Tools::displayError('You do not have permission to add here.');