diff --git a/ccserver/objectsdb.py b/ccserver/objectsdb.py
index efab3f7144f36b8cfb9be5f645e6c83a37efd657..0bb8b2dcefb9774ab8b9277598857a119c078150 100644
--- a/ccserver/objectsdb.py
+++ b/ccserver/objectsdb.py
@@ -51,6 +51,7 @@ class ObjectsDB(object):
 
         # The list of received message while update:
         self._msgs = []
+        self._requested = {} # object id -> set of tags
 
         # Total amount of query updates:
         self._nb_queries = 0
@@ -66,9 +67,10 @@ class ObjectsDB(object):
         '''
 
         with self._lock:
+            self._requested = {}
             self._nb_queries += 1
             self._update(ids, tags, tags_novalue)
-            self._process_responses()
+            self._process_responses(tags)
             self._update_user_defined(ids)
 
     def _update(self, ids=None, tags=None, tags_novalue=None):
@@ -113,12 +115,14 @@ class ObjectsDB(object):
             if '__parent' in obj:
                 # Current object is proxified by a parent:
                 parent = obj['__parent']
-                self._update_object(parent, tags, tags_novalue)
 
                 # Parent is removed from the list if it present (because
                 # it has been updated):
                 if parent['id'] in ids:
+                    self._update_object(parent, tags, tags_novalue)
                     ids.remove(parent['id'])
+                else:
+                    self._update_object(parent, (), (), only_udt=True)
 
                 # Search for sibling objects:
                 sg = set((o for o in ids if o.startswith('%s.' % parent['id'])))
@@ -153,8 +157,13 @@ class ObjectsDB(object):
                 user_tags = obj['__user_defined_tags']
 
             obj.update(user_tags)
+
+            # Delete ttls if present:
+            for tag in user_tags:
+                if (obj['id'], tag) in self._ttls:
+                    del self._ttls[(obj['id'], tag)]
     
-    def _process_responses(self):
+    def _process_responses(self, tags):
         '''
         Process the responses received from clients.
         '''
@@ -162,17 +171,32 @@ class ObjectsDB(object):
         msgs = self._server.manager.wait(frozenset(self._msgs), timeout=4)
         now = datetime.now()
 
+        # Avoid error if all tags are asked (not optimized case because we
+        # can't known the real list of tags:
+        if tags is None:
+            tags = ()
+
+        received = set()
+        
         for msg in msgs:
+            obj = msg['data']
+            assert isinstance(obj, TqlObject), 'data obj is not TqlObject'
+
             # Update tags if received from the peer:
             if msg.get('error') is not None:
                 logging.warning('Error from client while getting tags: %s',
                                 msg.get('error'))
+                for name in tags:
+                    if name in obj:
+                        old = obj[name]
+                        obj[name] = '#ERR#OLD:%s' % old
+                    else:
+                        obj[name] = '#ERR#'
+                    self._ttls[(obj['id'], name)] = now + timedelta(0, 10)
             else:
                 returned = msg['return']
-                obj = msg['data']
-
                 assert isinstance(returned, dict), 'returned tags is not a dict'
-                assert isinstance(obj, TqlObject), 'data obj is not TqlObject'
+                received.add(obj['id'])
 
                 for name, attrs in returned.iteritems():
                     obj[name] = attrs.get('value')
@@ -188,7 +212,15 @@ class ObjectsDB(object):
 
                     self._ttls[(obj['id'], name)] = tod
 
-    def _update_object(self, obj, tags, tags_novalue):
+        for oid in set(self._requested) - received:
+            obj = self.get_by_id(oid)
+            o_tags = self._requested[oid]
+            if o_tags is not None:
+                for name in o_tags:
+                    obj[name] = '#ERR#'
+                    self._ttls[(obj['id'], name)] = now + timedelta(0, 10)
+
+    def _update_object(self, obj, tags, tags_novalue, only_udt=False):
         '''
         Calculate the list of tags to request for a client, and send the
         request to the client.
@@ -204,6 +236,9 @@ class ObjectsDB(object):
             user_tags = parent['__user_defined_tags']
             client_id = parent['id']
 
+        if only_udt:
+            return
+
         if tags is not None:
             tags = set(tags)
             tags -= set(user_tags)
@@ -257,6 +292,7 @@ class ObjectsDB(object):
             msg_id = client.connection.async_call('get_tags', tags,
                                                   tags_novalue, _data=obj)
 
+        self._requested[obj['id']] = tags
         self._msgs.append(msg_id)
 
     def get_by_id(self, oid):