diff --git a/addons/crm/res_config.py b/addons/crm/res_config.py
index 5aac7c61fa2..42b08fb2f48 100644
--- a/addons/crm/res_config.py
+++ b/addons/crm/res_config.py
@@ -26,6 +26,33 @@ class crm_configuration(osv.TransientModel):
     _name = 'sale.config.settings'
     _inherit = ['sale.config.settings', 'fetchmail.config.settings']
 
+    def set_group_multi_salesteams(self, cr, uid, ids, context=None):
+        """ This method is automatically called by res_config as it begins
+            with set. It is used to implement the 'one group or another'
+            behavior. We have to perform some group manipulation by hand
+            because in res_config.execute(), set_* methods are called
+            after group_*; therefore writing on an hidden res_config file
+            could not work.
+            If group_multi_salesteams is checked: remove group_mono_salesteams
+            from group_user, remove the users. Otherwise, just ass
+            group_mono_salesteams in group_user.
+            The inverse logic about group_multi_salesteams is managed by the
+            normal behavior of 'group_multi_salesteams' field.
+        """
+        def ref(xml_id):
+            mod, xml = xml_id.split('.', 1)
+            return self.pool['ir.model.data'].get_object(cr, uid, mod, xml, context)
+
+        for obj in self.browse(cr, uid, ids, context=context):
+            config_group = ref('base.group_mono_salesteams')
+            base_group = ref('base.group_user')
+            if obj.group_multi_salesteams:
+                base_group.write({'implied_ids': [(3, config_group.id)]})
+                config_group.write({'users': [(3, u.id) for u in base_group.users]})
+            else:
+                base_group.write({'implied_ids': [(4, config_group.id)]})
+        return True
+
     _columns = {
         'group_fund_raising': fields.boolean("Manage Fund Raising",
             implied_group='crm.group_fund_raising',
@@ -34,10 +61,11 @@ class crm_configuration(osv.TransientModel):
             help="""Allows you to track your customers/suppliers claims and grievances.
                     This installs the module crm_claim."""),
         'module_crm_helpdesk': fields.boolean("Manage Helpdesk and Support",
-            help="""Allows you to communicate with Customer,  process Customer query, and provide better help and support. This installs the module crm_helpdesk."""),
-        'group_multi_salesteams': fields.boolean("Manage Sales Teams",
+            help="""Allows you to communicate with Customer, process Customer query, and provide better help and support. This installs the module crm_helpdesk."""),
+        'group_multi_salesteams': fields.boolean("Use Sales Teams",
             implied_group='base.group_multi_salesteams',
             help="""Allows you to use Sales Teams to manage your leads and opportunities."""),
     }
 
+
 # vim:expandtab:smartindent:tabstop=4:softtabstop=4:shiftwidth=4:
diff --git a/addons/crm/res_config_view.xml b/addons/crm/res_config_view.xml
index a6ec87b8243..1c460a12422 100644
--- a/addons/crm/res_config_view.xml
+++ b/addons/crm/res_config_view.xml
@@ -22,6 +22,14 @@
                             </div>
                         </div>
                     </group>
+                    <separator string="Sales Teams Configuration"/>
+                    <group>
+                        <label for="id" string="Use Sales Teams"/>
+                        <div>
+                            <field name="group_multi_salesteams" class="oe_inline"/>
+                            <label for="group_multi_salesteams"/>
+                        </div>
+                    </group>
 	            </div>
             </field>
         </record>
diff --git a/addons/crm/security/crm_security.xml b/addons/crm/security/crm_security.xml
index c51c00f0b88..34137dc0fac 100644
--- a/addons/crm/security/crm_security.xml
+++ b/addons/crm/security/crm_security.xml
@@ -23,6 +23,14 @@
         <field name="users" eval="[(4, ref('base.user_root'))]"/>
     </record>
 
+    <record id="base.group_mono_salesteams" model="res.groups">
+        <field name="name">Do Not Use Sales Teams</field>
+        <field name="category_id" ref="base.module_category_hidden"/>
+    </record>
+    <record id="base.group_user" model="res.groups">
+        <field name="implied_ids" eval="[(4, ref('base.group_mono_salesteams'))]"/>
+    </record>
+
     <record id="base.group_multi_salesteams" model="res.groups">
         <field name="name">Manage Sales Teams</field>
         <field name="category_id" ref="base.module_category_hidden"/>