diff --git a/addons/purchase/purchase.py b/addons/purchase/purchase.py
index 0626f785241..56eb12147c7 100644
--- a/addons/purchase/purchase.py
+++ b/addons/purchase/purchase.py
@@ -31,6 +31,7 @@ import openerp.addons.decimal_precision as dp
 from openerp.osv.orm import browse_record, browse_null
 from openerp.tools import DEFAULT_SERVER_DATE_FORMAT, DEFAULT_SERVER_DATETIME_FORMAT, DATETIME_FORMATS_MAP
 
+
 class purchase_order(osv.osv):
 
     def _amount_all(self, cr, uid, ids, field_name, arg, context=None):
@@ -155,12 +156,19 @@ class purchase_order(osv.osv):
 
     def _get_picking_ids(self, cr, uid, ids, field_names, args, context=None):
         res = {}
-        for purchase_id in ids:
-            picking_ids = set()
-            move_ids = self.pool.get('stock.move').search(cr, uid, [('purchase_line_id.order_id', '=', purchase_id)], context=context)
-            for move in self.pool.get('stock.move').browse(cr, uid, move_ids, context=context):
-                picking_ids.add(move.picking_id.id)
-            res[purchase_id] = list(picking_ids)
+        query = """
+        SELECT picking_id, po.id FROM stock_picking p, stock_move m, purchase_order_line pol, purchase_order po
+            WHERE po.id in %s and po.id = pol.order_id and pol.id = m.purchase_line_id and m.picking_id = p.id
+            GROUP BY picking_id, po.id
+             
+        """
+        cr.execute(query, (tuple(ids), ))
+        picks = cr.fetchall()
+        for pick in picks:
+            if not res.get(pick[1]):
+                res[pick[1]] = [pick[0]]
+            else:
+                res[pick[1]].append(pick[0])
         return res
 
     STATE_SELECTION = [
diff --git a/addons/purchase/stock.py b/addons/purchase/stock.py
index 5989584793d..dde18dca2c3 100644
--- a/addons/purchase/stock.py
+++ b/addons/purchase/stock.py
@@ -35,7 +35,7 @@ class stock_move(osv.osv):
             ids = [ids]
         res = super(stock_move, self).write(cr, uid, ids, vals, context=context)
         from openerp import workflow
-        if 'state' in vals:
+        if 'state' in vals and vals['state'] in ['done', 'cancel']:
             for move in self.browse(cr, uid, ids, context=context):
                 if move.purchase_line_id and move.purchase_line_id.order_id:
                     order_id = move.purchase_line_id.order_id.id
diff --git a/addons/stock/stock.py b/addons/stock/stock.py
index 57fc427dc3e..041417797be 100644
--- a/addons/stock/stock.py
+++ b/addons/stock/stock.py
@@ -1488,11 +1488,12 @@ class stock_move(osv.osv):
             if move.product_id.uom_id.category_id.id != move.product_uom.category_id.id:
                 return False
         return True
-
+ 
     _constraints = [
         (_check_uom,
             'You try to move a product using a UoM that is not compatible with the UoM of the product moved. Please use an UoM in the same UoM category.',
             ['product_uom'])]
+     
 
     def copy_data(self, cr, uid, id, default=None, context=None):
         if default is None: