Comment 2 for bug 794312

StacktraceTop:
 g_type_check_instance_cast (type_instance=0x2849cb0, iface_type=42195904) at /build/buildd/glib2.0-2.28.6/./gobject/gtype.c:3995
 ido_calendar_menu_item_set_date (menuitem=0x27d7440, year=2011, month=5, day=7) at idocalendarmenuitem.c:383
 menu_visible_notfy_cb (menu=0x2671700, pspec=<value optimized out>, user_data=<value optimized out>) at indicator-datetime.c:290
 g_closure_invoke (closure=0x27ca0a0, return_value=0x0, n_param_values=2, param_values=0x2781d90, invocation_hint=0x7fff23227bb0) at /build/buildd/glib2.0-2.28.6/./gobject/gclosure.c:767
 signal_emit_unlocked_R (node=<value optimized out>, detail=275, instance=0x2671700, emission_return=0x0, instance_and_params=0x2781d90) at /build/buildd/glib2.0-2.28.6/./gobject/gsignal.c:3252