diff --git a/ges/ges-container.c b/ges/ges-container.c
index d6ec21d223..e6f6949dad 100644
--- a/ges/ges-container.c
+++ b/ges/ges-container.c
@@ -127,6 +127,7 @@ _free_mapping (ChildMapping * mapping)
     ges_timeline_element_set_parent (child, NULL);
     gst_object_unref (child);
   }
+
   g_slice_free (ChildMapping, mapping);
 }
 
@@ -344,14 +345,11 @@ _deep_copy (GESTimelineElement * element, GESTimelineElement * copy)
   GESContainer *self = GES_CONTAINER (element), *ccopy = GES_CONTAINER (copy);
 
   for (tmp = GES_CONTAINER_CHILDREN (element); tmp; tmp = tmp->next) {
-    ChildMapping *map;
-
-    map =
-        g_slice_dup (ChildMapping, g_hash_table_lookup (self->priv->mappings,
-            tmp->data));
+    ChildMapping *map, *orig_map;
+    orig_map = g_hash_table_lookup (self->priv->mappings, tmp->data);
+    map = g_slice_new0 (ChildMapping);
     map->child = ges_timeline_element_copy (tmp->data, TRUE);
-    map->start_notifyid = 0;
-    map->duration_notifyid = 0;
+    map->start_offset = orig_map->start_offset;
 
     ccopy->priv->copied_children = g_list_prepend (ccopy->priv->copied_children,
         map);
@@ -384,8 +382,7 @@ _paste (GESTimelineElement * element, GESTimelineElement * ref,
       return NULL;
     }
 
-    ges_timeline_element_set_timeline (GES_TIMELINE_ELEMENT (ncontainer),
-        GES_TIMELINE_ELEMENT_TIMELINE (ref));
+    /* for GESGroups, this may register the group on the timeline */
     ges_container_add (ncontainer, nchild);
   }
 
diff --git a/ges/ges-group.c b/ges/ges-group.c
index 097b2f629a..b99ba7c7db 100644
--- a/ges/ges-group.c
+++ b/ges/ges-group.c
@@ -685,27 +685,6 @@ _group (GList * containers)
   return ret;
 }
 
-static GESTimelineElement *
-_paste (GESTimelineElement * element, GESTimelineElement * ref,
-    GstClockTime paste_position)
-{
-  GESTimelineElement *ngroup =
-      GES_TIMELINE_ELEMENT_CLASS (parent_class)->paste (element, ref,
-      paste_position);
-
-  if (ngroup) {
-    if (GES_CONTAINER_CHILDREN (ngroup)) {
-      timeline_add_group (GES_TIMELINE_ELEMENT_TIMELINE (GES_CONTAINER_CHILDREN
-              (ngroup)->data), GES_GROUP (element));
-      timeline_emit_group_added (GES_TIMELINE_ELEMENT_TIMELINE
-          (GES_CONTAINER_CHILDREN (ngroup)->data), GES_GROUP (element));
-    }
-  }
-
-  return ngroup;
-}
-
-
 /****************************************************
  *                                                  *
  *    GObject virtual methods implementation        *
@@ -781,7 +760,6 @@ ges_group_class_init (GESGroupClass * klass)
   element_class->set_max_duration = _set_max_duration;
   element_class->set_start = _set_start;
   element_class->set_priority = _set_priority;
-  element_class->paste = _paste;
 
   /* We override start, inpoint, duration and max-duration from GESTimelineElement
    * in order to makes sure those fields are not serialized.
diff --git a/ges/ges-timeline.c b/ges/ges-timeline.c
index 48563ffdd2..3c3dddfdf7 100644
--- a/ges/ges-timeline.c
+++ b/ges/ges-timeline.c
@@ -332,14 +332,15 @@ ges_timeline_dispose (GObject * object)
     ges_timeline_remove_track (GES_TIMELINE (object), tl->tracks->data);
   UNLOCK_DYN (tl);
 
-  groups = g_list_copy (priv->groups);
+  /* NOTE: the timeline should not contain empty groups */
+  groups = g_list_copy_deep (priv->groups, (GCopyFunc) gst_object_ref, NULL);
   for (tmp = groups; tmp; tmp = tmp->next) {
     GList *elems = ges_container_ungroup (tmp->data, FALSE);
 
     g_list_free_full (elems, gst_object_unref);
   }
-  g_list_free (priv->groups);
-  g_list_free (groups);
+  g_list_free_full (groups, gst_object_unref);
+  g_list_free_full (priv->groups, gst_object_unref);
 
   g_list_free_full (priv->auto_transitions, gst_object_unref);