diff --git a/trytond/ir/model.py b/trytond/ir/model.py
index 37c98a3acb..d00a922f33 100644
--- a/trytond/ir/model.py
+++ b/trytond/ir/model.py
@@ -234,15 +234,21 @@ class ModelData(OSV):
                 "data with the wrong model.")
             object_ref = self.pool.get(model)
             # XXX maybe use a browse instead:
-            db_values = object_ref.read(cursor, user, db_id, values.keys())
+            db_values = object_ref.browse(cursor, user, db_id)
 
             to_update = {}
             for key in values:
 
-                # first handle correctly the datas returned by read()
-                if object_ref._columns[key]._type == 'many2one':
-                    db_field = db_values[key] and db_values[key][0] or False
-                elif object_ref._columns[key]._type in ['one2one', 'one2many', "many2many"]:
+                # search the field type in the object or in a parent
+                if key in object_ref._columns:
+                    field_type = object_ref._columns[key]._type
+                else:
+                    field_type = object_ref._inherit_fields[key][2]._type
+
+                # handle the value regarding to the type
+                if field_type == 'many2one':
+                    db_field = db_values[key] and db_values[key].id or False
+                elif field_type in ['one2one', 'one2many', "many2many"]:
                     logger = Logger()
                     logger.notify_channel('init', LOG_WARNING,
                         'Field %s on %s : integrity not tested.'%(key, model))
diff --git a/trytond/res/user.py b/trytond/res/user.py
index 100778cf74..d19e58c6f4 100644
--- a/trytond/res/user.py
+++ b/trytond/res/user.py
@@ -69,7 +69,7 @@ class User(OSV):
         'action_id': fields.Many2One('ir.action', 'Home Action'),
         'menu_id': fields.Many2One('ir.action', 'Menu Action'),
         'groups_id': fields.Many2Many('res.group', 'res_group_user_rel',
-            'uid', 'gid', 'Groups'), 
+            'uid', 'gid', 'Groups'),
         'roles_id': fields.Many2Many('res.role', 'res_role_user_rel',
             'uid', 'rid', 'Roles'),
         #'company_id': fields.Many2One('res.company', 'Company'),