--- /usr/src-nfs/sys/kern/kern_clock.c	2010-06-30 03:38:25.000000000 -0500
+++ kern_clock.c	2010-07-01 02:19:39.048697991 -0500
@@ -232,7 +232,8 @@
 	panic("%s: possible deadlock detected for %p, blocked for %d ticks\n",
 						    __func__, td, tticks);
 					}
-				} else if (TD_IS_SLEEPING(td)) {
+				} else if (TD_IS_SLEEPING(td) &&
+				    TD_ON_SLEEPQ(td)) {
 
 					/* Handle ticks wrap-up. */
 					if (ticks < td->td_blktick) {