Fix for new field attributes names

invoice.py

@@ -190,7 +190,7 @@ class Invoice(OSV):
     def default_payment_term(self, cursor, user, context=None):
         payment_term_obj = self.pool.get('account.invoice.payment_term')
         payment_term_ids = payment_term_obj.search(cursor, user,
-                self.payment_term._domain, context=context)
+                self.payment_term.domain, context=context)
         if len(payment_term_ids) == 1:
             return payment_term_obj.name_get(cursor, user, payment_term_ids,
                     context=context)[0]