diff -r 6783e2ec60c0 xen/common/event_channel.c
--- a/xen/common/event_channel.c	Mon Jul 28 11:27:48 2008 +0100
+++ b/xen/common/event_channel.c	Thu Jul 31 16:55:14 2008 +0800
@@ -446,6 +446,9 @@ static long __evtchn_close(struct domain
     default:
         BUG();
     }
+
+    /* clear pending event to avoid unexpected behavior */
+    clear_bit(port1, &shared_info(d1, evtchn_pending));
 
     /* Reset binding to vcpu0 when the channel is freed. */
     chn1->state          = ECS_FREE;