diff --git a/addons/stock/stock.py b/addons/stock/stock.py
index f24cb7a669b..cfde0419a7b 100644
--- a/addons/stock/stock.py
+++ b/addons/stock/stock.py
@@ -968,6 +968,7 @@ class stock_picking(osv.osv):
         """
         quant_obj = self.pool.get("stock.quant")
         pack_obj = self.pool.get("stock.quant.package")
+        uom_obj = self.pool.get('product.uom')
         res = {} # Qty still to do from ops
         res2 = {} #what is left from moves
         resneg= {} #Number of negative quants to create for move/op
@@ -992,7 +993,7 @@ class stock_picking(osv.osv):
                 if ops.product_id:
                     # Match with moves
                     move_ids = ops.product_id.id in products_moves and filter(lambda x: res2[x.id] > 0, products_moves[ops.product_id.id]) or []
-                    qty_to_do = ops.product_qty
+                    qty_to_do = uom_obj._compute_qty(cr, uid, ops.product_uom_id.id, ops.product_qty, to_uom_id=ops.product_id.uom_id.id)
                     while qty_to_do > 0 and move_ids:
                         move = move_ids.pop()
                         if res2[move.id] > qty_to_do: 
@@ -3147,13 +3148,18 @@ class stock_pack_operation(osv.osv):
         return res
 
     def product_id_change(self, cr, uid, ids, product_id, product_uom_id, product_qty, context=None):
+        res = self.on_change_tests(cr, uid, ids, product_id, product_uom_id, product_qty, context=context)
+        if product_id and not product_uom_id:
+            product = self.pool.get('product.product').browse(cr, uid, product_id, context=context)
+            res['value']['product_uom_id'] = product.uom_id.id
+        return res
+
+    def on_change_tests(self, cr, uid, ids, product_id, product_uom_id, product_qty, context=None):
         res = {'value': {}}
         uom_obj = self.pool.get('product.uom')
         if product_id:
             product = self.pool.get('product.product').browse(cr, uid, product_id, context=context)
-            if not product_uom_id:
-                product_uom_id = product.uom_id.id
-                res['value']['product_uom_id'] = product_uom_id
+            product_uom_id = product_uom_id or product.uom_id.id
             selected_uom = uom_obj.browse(cr, uid, product_uom_id, context=context)
             if selected_uom.category_id.id != product.uom_id.category_id.id:
                 res['warning'] = {
diff --git a/addons/stock/stock_view.xml b/addons/stock/stock_view.xml
index ca92a76b43e..00f2f286c84 100644
--- a/addons/stock/stock_view.xml
+++ b/addons/stock/stock_view.xml
@@ -794,11 +794,11 @@
                             <field name="pack_operation_ids" attrs="{'invisible': [('pack_operation_exist', '=', False)]}" context="{'default_owner_id': owner_id}">
                                 <tree editable="top">   
                                     <field name="product_id" on_change='product_id_change(product_id, product_uom_id, product_qty, context)'/>
-                                    <field name="product_uom_id" groups="product.group_uom" on_change='product_id_change(product_id, product_uom_id, product_qty, context)'/>
+                                    <field name="product_uom_id" groups="product.group_uom" on_change='on_change_tests(product_id, product_uom_id, product_qty, context)'/>
                                     <field name="lot_id" domain="[('product_id','=?', product_id)]" context="{'product_id': product_id}" groups="stock.group_production_lot"/>
                                     <field name="package_id" groups="stock.group_tracking_lot"/>
                                     <field name="owner_id" groups="stock.group_tracking_owner"/>
-                                    <field name="product_qty" attrs="{'required': [('product_id', '!=', False)]}" on_change='product_id_change(product_id, product_uom_id, product_qty, context)'/>
+                                    <field name="product_qty" attrs="{'required': [('product_id', '!=', False)]}" on_change='on_change_tests(product_id, product_uom_id, product_qty, context)'/>
                                     <field name="result_package_id" groups="stock.group_tracking_lot"/>
                                 </tree>
                             </field>