diff --git a/addons/mail/mail_group.py b/addons/mail/mail_group.py
index 83d0705c4e0..48bc6d4723c 100644
--- a/addons/mail/mail_group.py
+++ b/addons/mail/mail_group.py
@@ -49,12 +49,6 @@ class mail_group(osv.osv):
     _name = 'mail.group'
     _inherit = ['mail.thread']
 
-    def action_group_join(self, cr, uid, ids, context={}):
-        return self.message_subscribe(cr, uid, ids, context=context);
-    
-    def action_group_leave(self, cr, uid, ids, context={}):
-        return self.message_unsubscribe(cr, uid, ids, context=context);
-
     def onchange_photo(self, cr, uid, ids, value, context=None):
         if not value:
             return {'value': {'avatar_big': value, 'avatar': value} }
@@ -118,19 +112,28 @@ class mail_group(osv.osv):
         'responsible_id': fields.many2one('res.users', string='Responsible',
                             ondelete='set null', required=True, select=1,
                             help="Responsible of the group that has all rights on the record."),
-        'public': fields.boolean('Public', help='This group is visible by non members. Invisible groups can add members through the invite button.'),
-        'models': fields.many2many('ir.model', rel='mail_group_models_rel', id1='mail_group_id', id2='model_id',
+        'public': fields.boolean('Public', help='This group is visible by non members. \
+                            Invisible groups can add members through the invite button.'),
+        'models': fields.many2many('ir.model', rel='mail_group_models_rel',
+                            id1='mail_group_id', id2='model_id',
                             string='Linked models', help='Linked models'),
-        'photo_big': fields.binary('Full-size photo', help='Field holding the full-sized PIL-supported and base64 encoded version of the group image. The photo field is used as an interface for this field.'),
+        'photo_big': fields.binary('Full-size photo', help='Field holding \
+                            the full-sized PIL-supported and base64 encoded \
+                            version of the group image. The photo field is \
+                            used as an interface for this field.'),
         'photo': fields.function(_get_photo, fnct_inv=_set_photo, string='Photo', type="binary",
             store = {
                 'mail.group': (lambda self, cr, uid, ids, c={}: ids, ['photo_big'], 10),
             }, help='Field holding the automatically resized (128x128) PIL-supported and base64 encoded version of the group image.'),
-        'member_ids': fields.function(get_member_ids, fnct_search=search_member_ids, type='many2many',
-                        relation='res.users', string='Group members', multi='get_member_ids'),
-        'member_count': fields.function(get_member_ids, type='integer', string='Member count', multi='get_member_ids'),
-        'is_subscriber': fields.function(get_member_ids, type='boolean', string='Joined', multi='get_member_ids'),
-        'last_month_msg_nbr': fields.function(get_last_month_msg_nbr, type='integer', string='Messages count for last month'),
+        'member_ids': fields.function(get_member_ids, fnct_search=search_member_ids,
+                            type='many2many', relation='res.users',
+                            string='Group members', multi='get_member_ids'),
+        'member_count': fields.function(get_member_ids, type='integer',
+                            string='Member count', multi='get_member_ids'),
+        'is_subscriber': fields.function(get_member_ids, type='boolean',
+                            string='Joined', multi='get_member_ids'),
+        'last_month_msg_nbr': fields.function(get_last_month_msg_nbr, type='integer',
+                            string='Messages count for last month'),
     }
 
     _defaults = {
@@ -138,3 +141,36 @@ class mail_group(osv.osv):
         'responsible_id': (lambda s, cr, uid, ctx: uid),
         'photo': _get_default_photo,
     }
+    
+    def message_load(self, cr, uid, ids, limit=100, offset=0, domain=[], ascent=False, root_ids=[], context=None):
+        """ Override OpenChatter method.
+            if models attribute is set: search all messages from that model
+            else: as usual
+            :param domain: domain to add to the search; especially child_of
+                           is interesting when dealing with threaded display
+            :param ascent: performs an ascended search; will add to fetched msgs
+                           all their parents until root_ids
+            :param root_ids: for ascent search
+            :param root_ids: root_ids when performing an ascended search
+        """
+        search_domain = []
+        for group in self.browse(cr, uid, ids, context=context):
+            # call super to have default message ids
+            message_obj = self.pool.get('mail.message')
+            group_msgs = super(mail_group, self).message_load(cr, uid, ids, limit, offset, domain, ascent, root_ids, context)
+            msg_ids = map(itemgetter('id'), group_msgs)
+            search_domain = ['|', '&', ('model', '=', self._name), ('id', 'in', ids)]
+            # add message ids linked to group models
+            model_list = []
+            for model in group.models:
+                model_list.append(model.model)
+            search_domain.append(('model', 'in', model_list))
+            msg_ids += message_obj.search(cr, uid, search_domain, limit=limit, offset=offset, context=context)
+        return message_obj.read(cr, uid, msg_ids, context=context)
+    
+    def action_group_join(self, cr, uid, ids, context=None):
+        return self.message_subscribe(cr, uid, ids, context=context)
+    
+    def action_group_leave(self, cr, uid, ids, context=None):
+        return self.message_unsubscribe(cr, uid, ids, context=context)
+