--- zzzz-none-000/linux-2.6.28.10/net/sched/sch_tbf.c	2009-05-02 18:54:43.000000000 +0000
+++ puma5-6360-529/linux-2.6.28.10/net/sched/sch_tbf.c	2009-10-23 13:23:35.000000000 +0000
@@ -288,7 +288,7 @@
 	if (max_size < 0)
 		goto done;
 
-	if (qopt->limit > 0) {
+	if (qopt->limit > 0 && q->qdisc == &noop_qdisc) {
 		child = fifo_create_dflt(sch, &bfifo_qdisc_ops, qopt->limit);
 		if (IS_ERR(child)) {
 			err = PTR_ERR(child);