diff --git a/bin/addons/base/ir/ir_rule.py b/bin/addons/base/ir/ir_rule.py
index ba508b48920..23981458606 100644
--- a/bin/addons/base/ir/ir_rule.py
+++ b/bin/addons/base/ir/ir_rule.py
@@ -21,11 +21,14 @@
 
 from osv import fields,osv
 import time
+from operator import itemgetter
+from functools import partial
 import tools
 from tools.safe_eval import safe_eval as eval
 
 class ir_rule(osv.osv):
     _name = 'ir.rule'
+    _MODES = ['read', 'write', 'create', 'unlink']
 
     def _domain_force_get(self, cr, uid, ids, field_name, arg, context={}):
         res = {}
@@ -45,13 +48,7 @@ class ir_rule(osv.osv):
         return res
 
     def _check_model_obj(self, cr, uid, ids, context={}):
-        model_obj = self.pool.get('ir.model')
-        for rule in self.browse(cr, uid, ids, context):
-            model = model_obj.browse(cr, uid, rule.model_id.id, context).model
-            obj = self.pool.get(model)
-            if isinstance(obj, osv.osv_memory):
-                return False
-        return True
+        return not any(isinstance(self.pool.get(rule.model_id.model), osv.osv_memory) for rule in self.browse(cr, uid, ids, context))
 
     _columns = {
         'name': fields.char('Name', size=128, select=1),
@@ -90,6 +87,8 @@ class ir_rule(osv.osv):
 
     @tools.cache()
     def _compute_domain(self, cr, uid, model_name, mode="read"):
+        if mode not in self._MODES:
+            raise ValueError('Invalid mode: %r' % (mode,))
         group_rule = {}
         global_rules = []
 
@@ -115,6 +114,24 @@ class ir_rule(osv.osv):
             dom += self.domain_create(cr, uid, value)
         return dom
 
+    def clear_cache(self, cr, uid):
+        cr.execute("""SELECT DISTINCT m.model
+                        FROM ir_rule r
+                        JOIN ir_model m
+                          ON r.model_id = m.id
+                       WHERE r.global
+                          OR EXISTS (SELECT 1
+                                       FROM rule_group_rel g_rel
+                                       JOIN res_groups_users_rel u_rel
+                                         ON g_rel.group_id = u_rel.gid
+                                      WHERE g_rel.rule_group_id = r.id
+                                        AND u_rel.uid = %s)
+                    """, (uid,))
+        models = map(itemgetter(0), cr.fetchall())
+        clear = partial(self._compute_domain.clear_cache, cr.dbname, uid)
+        [clear(model, mode) for model in models for mode in self._MODES]
+
+
     def domain_get(self, cr, uid, model_name, mode='read', context={}):
         dom = self._compute_domain(cr, uid, model_name, mode=mode)
         if dom:
diff --git a/bin/addons/base/res/res_company.py b/bin/addons/base/res/res_company.py
index c076eef612a..4b6ec1dc00a 100644
--- a/bin/addons/base/res/res_company.py
+++ b/bin/addons/base/res/res_company.py
@@ -133,12 +133,12 @@ class res_company(osv.osv):
         ids = self._get_company_children(cr, uid, company)
         return ids
 
+    @tools.cache()
     def _get_company_children(self, cr, uid=None, company=None):
         if not company:
             return []
         ids =  self.search(cr, uid, [('parent_id','child_of',[company])])
         return ids
-    _get_company_children = tools.cache()(_get_company_children)
 
     def _get_partner_hierarchy(self, cr, uid, company_id, context={}):
         if company_id:
@@ -168,7 +168,6 @@ class res_company(osv.osv):
 
     def write(self, cr, *args, **argv):
         self.cache_restart(cr)
-        # Restart the cache on the company_get method
         return super(res_company, self).write(cr, *args, **argv)
 
     def _get_euro(self, cr, uid, context={}):
diff --git a/bin/addons/base/res/res_user.py b/bin/addons/base/res/res_user.py
index 9040f90be95..c71982527d8 100644
--- a/bin/addons/base/res/res_user.py
+++ b/bin/addons/base/res/res_user.py
@@ -20,9 +20,9 @@
 ##############################################################################
 
 from osv import fields,osv
-from osv.orm import except_orm, browse_record
+from osv.orm import browse_record
 import tools
-import operator
+from functools import partial
 import pytz
 import pooler
 from tools.translate import _
@@ -55,7 +55,6 @@ class groups(osv.osv):
                 raise osv.except_osv(_('Error'),
                         _('The name of the group can not start with "-"'))
         res = super(groups, self).write(cr, uid, ids, vals, context=context)
-        # Restart the cache on the company_get method
         self.pool.get('ir.model.access').call_cache_clearing_methods(cr)
         return res
 
@@ -332,11 +331,14 @@ class users(osv.osv):
         'groups_id': _get_group,
         'address_id': False,
     }
+
+    @tools.cache()
     def company_get(self, cr, uid, uid2, context=None):
         return self._get_company(cr, uid, context=context, uid2=uid2)
-    company_get = tools.cache()(company_get)
 
     def write(self, cr, uid, ids, values, context=None):
+        if not hasattr(ids, '__iter__'):
+            ids = [ids]
         if ids == [uid]:
             for key in values.keys():
                 if not (key in ('view', 'password','signature','action_id', 'company_id') or key.startswith('context_')):
@@ -344,9 +346,13 @@ class users(osv.osv):
             else:
                 uid = 1
         res = super(users, self).write(cr, uid, ids, values, context=context)
+
+        # clear caches linked to the users
         self.company_get.clear_cache(cr.dbname)
-        # Restart the cache on the company_get method
         self.pool.get('ir.model.access').call_cache_clearing_methods(cr)
+        clear = partial(self.pool.get('ir.rule').clear_cache, cr)
+        map(clear, ids)
+
         return res
 
     def unlink(self, cr, uid, ids, context=None):