diff --git a/addons/crm/calendar_event.py b/addons/crm/calendar_event.py
index df50d99b72b..4f57e364282 100644
--- a/addons/crm/calendar_event.py
+++ b/addons/crm/calendar_event.py
@@ -48,31 +48,11 @@ class calendar_attendee(osv.osv):
     _inherit = 'calendar.attendee'
     _description = 'Calendar Attendee'
 
-    def _compute_data(self, cr, uid, ids, name, arg, context=None):
-       """
-        @param self: The object pointer
-        @param cr: the current row, from the database cursor,
-        @param uid: the current user’s ID for security checks,
-        @param ids: List of compute data’s IDs
-        @param context: A standard dictionary for contextual values
-        """
-       name = name[0]
-       result = super(calendar_attendee, self)._compute_data(cr, uid, ids, name, arg, context=context)
-
-       for attdata in self.browse(cr, uid, ids, context=context):
-            id = attdata.id
-            result[id] = {}
-            if name == 'categ_id':
-                if attdata.ref and 'categ_id' in attdata.ref._columns:
-                    result[id][name] = (attdata.ref.categ_id.id, attdata.ref.categ_id.name,)
-                else:
-                    result[id][name] = False
-       return result
+    def _noop(self, cr, uid, ids, name, arg, context=None):
+       return dict.fromkeys(ids,False)
 
     _columns = {
-        'categ_id': fields.function(_compute_data, \
-                        string='Event Type', type="many2one", \
-                        relation="crm.case.categ", multi='categ_id'),
+        'categ_id': fields.function(_noop, string='Event Type', deprecated="Unused Field - TODO : Remove it in trunk", type="many2one", relation="crm.case.categ"),
     }
 
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