diff --git a/addons/stock/stock.py b/addons/stock/stock.py
index 8c93c5a5ae0..3f491af644c 100644
--- a/addons/stock/stock.py
+++ b/addons/stock/stock.py
@@ -1243,14 +1243,28 @@ class stock_picking(osv.osv):
                     too_few.append(move)
                 else:
                     too_many.append(move)
-
+                
+                #Change cost price according to 
+                user = self.pool.get('res.users').browse(cr, uid, uid, context=context)
+                product = product_obj.browse(cr, uid, move.product_id.id, context=context)
+                company_id = move.company_id.id
+                ctx = context.copy()
+                if company_id != user.company_id.id:
+                    #test if I could do this with a read instead
+                    ctx['force_company'] = move.company_id.id
+                    product = product_obj.browse(cr, uid, move.product_id.id, context=ctx)
+                    cost_method = product.cost_method
+                    product_price = product.standard_price
+                else:
+                    cost_method = move.product_id.cost_method
+                
                 # Average price computation
-                if (pick.type == 'in') and (move.product_id.cost_method == 'average'):
-                    product = product_obj.browse(cr, uid, move.product_id.id)
+                if (pick.type == 'in') and (cost_method == 'average'): 
+                    
                     move_currency_id = move.company_id.currency_id.id
                     context['currency_id'] = move_currency_id
                     qty = uom_obj._compute_qty(cr, uid, product_uom, product_qty, product.uom_id.id)
-
+                    
                     if product.id in product_avail:
                         product_avail[product.id] += qty
                     else:
@@ -1264,12 +1278,12 @@ class stock_picking(osv.osv):
                         if product.qty_available <= 0:
                             new_std_price = new_price
                         else:
-                            # Get the standard price
+                            # Get the standard price -> This should be company_dependent
                             amount_unit = product.price_get('standard_price', context=context)[product.id]
                             new_std_price = ((amount_unit * product_avail[product.id])\
                                 + (new_price * qty))/(product_avail[product.id] + qty)
-                        # Write the field according to price type field
-                        product_obj.write(cr, uid, [product.id], {'standard_price': new_std_price})
+                        # Write the field according to price type field, company dependence in ctx
+                        product_obj.write(cr, uid, [product.id], {'standard_price': new_std_price}, context=ctx)
 
                         # Record the values that were chosen in the wizard, so they can be
                         # used for inventory valuation if real-time valuation is enabled.
@@ -1278,7 +1292,7 @@ class stock_picking(osv.osv):
                                  'price_currency_id': product_currency})
 
                 #Average price computation when returning products
-                if (pick.type == 'out') and (move.product_id.cost_method == 'average'):
+                if (pick.type == 'out') and (cost_method == 'average'):
                     orig_move_id = move_obj.search(cr, uid, [('move_history_ids2', 'in', [move.id])], context=context)
                     if len(orig_move_id) == 1:
                         #Is it ok to repeat code here?
@@ -1292,6 +1306,7 @@ class stock_picking(osv.osv):
                             product_avail[product.id] += qty
                         else:
                             product_avail[product.id] = product.qty_available
+                            
                         if qty > 0:
                             new_price = currency_obj.compute(cr, uid, product_currency,
                                 move_currency_id, move_orig.price_unit)
@@ -1299,10 +1314,12 @@ class stock_picking(osv.osv):
                                 product.uom_id.id)
                             # Get the standard price
                             amount_unit = product.price_get('standard_price', context=context)[product.id]
-                            new_std_price = ((amount_unit * product_avail[product.id])\
-                                - (new_price * qty))/(product_avail[product.id] - qty)
-                            # Write the field according to price type field
-                            product_obj.write(cr, uid, [product.id], {'standard_price': new_std_price})
+                            #Check new stock is not zero or negative:
+                            if (product_avail[product.id]- qty) > 0:
+                                new_std_price = ((amount_unit * product_avail[product.id])\
+                                                 - (new_price * qty))/(product_avail[product.id] - qty)
+                                # Write the field according to price type field
+                                product_obj.write(cr, uid, [product.id], {'standard_price': new_std_price})
 
                             # Record the values that were chosen in the wizard, so they can be
                             # used for inventory valuation if real-time valuation is enabled.