On 3550, when priority / expedite queue is configured, it is enabled on queue #4, not #1 as the answer states. I guess, 3560 is the same... "more info" points to 3550 config guide..
Ok, I found that 3550 differs here when compared to 3560: on 3550 PQ is #4, on 3560 PQ is on #1. However the link provided under more info button is misleading. Here you'll find a good doc on this topic: