diff --git a/addons/purchase/purchase.py b/addons/purchase/purchase.py
index be2803261e7..4688b752578 100644
--- a/addons/purchase/purchase.py
+++ b/addons/purchase/purchase.py
@@ -679,12 +679,11 @@ class purchase_order(osv.osv):
     def action_cancel(self, cr, uid, ids, context=None):
         for purchase in self.browse(cr, uid, ids, context=context):
             for pick in purchase.picking_ids:
-                if pick.state not in ('draft', 'cancel'):
+                if pick.state not in ('draft', 'cancel', 'confirmed'):
                     raise osv.except_osv(
                         _('Unable to cancel the purchase order %s.') % (purchase.name),
                         _('First cancel all receipts related to this purchase order.'))
-            self.pool.get('stock.picking') \
-                .signal_workflow(cr, uid, map(attrgetter('id'), purchase.picking_ids), 'button_cancel')
+            self.pool.get('stock.picking').action_cancel(cr, uid, map(attrgetter('id'), purchase.picking_ids), context=context)
             for inv in purchase.invoice_ids:
                 if inv and inv.state not in ('cancel', 'draft'):
                     raise osv.except_osv(
@@ -692,9 +691,6 @@ class purchase_order(osv.osv):
                         _('You must first cancel all invoices related to this purchase order.'))
             self.pool.get('account.invoice') \
                 .signal_workflow(cr, uid, map(attrgetter('id'), purchase.invoice_ids), 'invoice_cancel')
-            self.pool['purchase.order.line'].write(cr, uid, [l.id for l in  purchase.order_line],
-                    {'state': 'cancel'})
-        self.write(cr, uid, ids, {'state': 'cancel'})
         self.set_order_line_status(cr, uid, ids, 'cancel', context=context)
         self.signal_workflow(cr, uid, ids, 'purchase_cancel')
         return True
diff --git a/addons/purchase/purchase_view.xml b/addons/purchase/purchase_view.xml
index 239bc990ff2..1ccd8af6011 100644
--- a/addons/purchase/purchase_view.xml
+++ b/addons/purchase/purchase_view.xml
@@ -202,8 +202,7 @@
                     <button name="view_picking" string="Receive Products" type="object" attrs="{'invisible': ['|', ('shipped','=',True), ('state','!=', 'approved')]}" class="oe_highlight"/>
                     <button name="view_invoice" string="Receive Invoice" type="object" attrs="{'invisible': ['|', ('invoice_method','in', ['picking', 'manual']), '|', ('state','!=', 'approved'), ('invoiced','=',True) ]}" class="oe_highlight"/>
                     <button name="action_cancel_draft" states="cancel,sent,confirmed" string="Set to Draft" type="object" />
-                    <button name="purchase_cancel" states="draft,confirmed,sent,bid" string="Cancel"/>
-                    <button name="action_cancel" states="approved,except_picking,except_invoice" string="Cancel" type="object" />
+                    <button name="action_cancel" states="draft,confirmed,sent,bid,approved,except_picking,except_invoice" string="Cancel" type="object" />
                     <field name="state" widget="statusbar" statusbar_visible="draft,sent,bid,approved,done" statusbar_colors='{"except_picking":"red","except_invoice":"red","confirmed":"blue"}' readonly="1"/>
                 </header>
                 <sheet>