diff --git a/addons/purchase/purchase.py b/addons/purchase/purchase.py
index 7d17364f369..200be4a593a 100644
--- a/addons/purchase/purchase.py
+++ b/addons/purchase/purchase.py
@@ -293,6 +293,27 @@ class purchase_order(osv.osv):
         fiscal_position = supplier.property_account_position and supplier.property_account_position.id or False
         return {'value':{'pricelist_id': pricelist, 'fiscal_position': fiscal_position}}
 
+    def invoice_open(self, cr, uid, ids, context=None):
+        mod_obj = self.pool.get('ir.model.data')
+        act_obj = self.pool.get('ir.actions.act_window')
+
+        result = mod_obj.get_object_reference(cr, uid, 'account', 'action_invoice_tree2')
+        id = result and result[1] or False
+        result = act_obj.read(cr, uid, [id], context=context)[0]
+        inv_ids = []
+        for po in self.browse(cr, uid, ids, context=context):
+            inv_ids+= [invoice.id for invoice in po.invoice_ids]
+        if not inv_ids:
+            raise osv.except_osv(_('Error!'), _('Please create Invoices.'))
+         #choose the view_mode accordingly
+        if len(inv_ids)>1:
+            result['domain'] = "[('id','in',["+','.join(map(str, inv_ids))+"])]"
+        else:
+            res = mod_obj.get_object_reference(cr, uid, 'account', 'invoice_supplier_form')
+            result['views'] = [(res and res[1] or False, 'form')]
+            result['res_id'] = inv_ids and inv_ids[0] or False
+        return result
+
     def view_invoice(self, cr, uid, ids, context=None):
         '''
         This function returns an action that display existing invoices of given sale order ids. It can either be a in a list or in a form view, if there is only one invoice to show.
@@ -547,7 +568,6 @@ class purchase_order(osv.osv):
             'invoice_state': '2binvoiced' if order.invoice_method == 'picking' else 'none',
             'type': 'in',
             'partner_id': order.dest_address_id.id or order.partner_id.id,
-            'invoice_state': '2binvoiced' if order.invoice_method == 'picking' else 'none',
             'purchase_id': order.id,
             'company_id': order.company_id.id,
             'move_lines' : [],
diff --git a/addons/purchase/purchase_view.xml b/addons/purchase/purchase_view.xml
index cff258e3017..db71a969fbe 100644
--- a/addons/purchase/purchase_view.xml
+++ b/addons/purchase/purchase_view.xml
@@ -282,8 +282,6 @@
                                     <field name="date_approve" groups="base.group_no_one"/>
                                 </group>
                             </group>
-                            <separator string="Invoices"/>
-                            <field name="invoice_ids" context="{'type':'in_invoice', 'journal_type':'purchase'}"/>
                         </page>
                     </notebook>
                 </sheet>
diff --git a/addons/purchase/stock_view.xml b/addons/purchase/stock_view.xml
index 9e5aa2e074e..188baeccd69 100644
--- a/addons/purchase/stock_view.xml
+++ b/addons/purchase/stock_view.xml
@@ -48,6 +48,8 @@
                         <button type="object"
                             name="view_picking"
                             string="Incoming Shipments" states="approved"/>
+                        <button type="object"  name="invoice_open"
+                            string="Invoices" attrs="{'invisible': [('state', '=', 'draft')]}"/> 
                     </div>
                 </xpath>
             </field>
diff --git a/addons/stock/stock_sequence.xml b/addons/stock/stock_sequence.xml
index 6c0b3e84cf2..c3569c48c3e 100644
--- a/addons/stock/stock_sequence.xml
+++ b/addons/stock/stock_sequence.xml
@@ -17,7 +17,7 @@
         
         <record id="seq_type_picking_internal" model="ir.sequence.type">
             <field name="name">Picking INT</field>
-            <field name="code">stock.picking.internal</field>
+            <field name="code">stock.picking</field>
         </record>
 
         <!--
@@ -42,7 +42,7 @@
         
         <record id="seq_picking_internal" model="ir.sequence">
             <field name="name">Picking INT</field>
-            <field name="code">stock.picking.internal</field>
+            <field name="code">stock.picking</field>
             <field name="prefix">INT/</field>
             <field name="padding">5</field>
             <field name="company_id" eval="False"/>