diff --git a/addons/calendar/calendar.py b/addons/calendar/calendar.py
index 22d56953e62..34a348c5b25 100644
--- a/addons/calendar/calendar.py
+++ b/addons/calendar/calendar.py
@@ -994,7 +994,6 @@ class calendar_event(osv.Model):
                 sort_fields[ord] = '%s-%s' % (browse_event[ord], r_date.strftime("%Y%m%d%H%M%S"))
             else:
                 sort_fields[ord] = browse_event[ord]
-                'If we sort on FK, we obtain a browse_record, so we need to sort on name_get'
                 if type(browse_event[ord]) is openerp.osv.orm.browse_record:
                     name_get = browse_event[ord].name_get()
                     if len(name_get) and len(name_get[0]) >= 2:
@@ -1401,7 +1400,8 @@ class calendar_event(osv.Model):
         for arg in args:
             if arg[0] == 'id':
                 for n, calendar_id in enumerate(arg[2]):
-                    arg[2][n] = calendar_id.split('-')[0]
+                    if isinstance(calendar_id, str):
+                        arg[2][n] = calendar_id.split('-')[0]
         return super(calendar_event, self)._name_search(cr, user, name=name, args=args, operator=operator, context=context, limit=limit, name_get_uid=name_get_uid)
 
     def write(self, cr, uid, ids, values, context=None):