diff -Naurp linux-2.5.75-mm1/kernel/sched.c linux-2.5.75-test/kernel/sched.c
--- linux-2.5.75-mm1/kernel/sched.c	2003-07-12 10:04:21.000000000 +1000
+++ linux-2.5.75-test/kernel/sched.c	2003-07-12 10:05:34.000000000 +1000
@@ -1333,7 +1333,7 @@ void scheduler_tick(int user_ticks, int 
 		p->time_slice = task_timeslice(p);
 		p->first_time_slice = 0;
 
-		if (!TASK_INTERACTIVE(p) || EXPIRED_STARVING(rq)) {
+		if (!TASK_INTERACTIVE(p) || EXPIRED_STARVING(rq) || iso_task(p)) {
 			if (!rq->expired_timestamp)
 				rq->expired_timestamp = jiffies;
 			enqueue_task(p, rq->expired);