meters but no sound in STP

STP was working perfectly on my new macbook pro.

But now I get no audio, no sound.

The meters show that audio is there, whether I audtion a clip

or place it in the timeline.

But I hear nothing.

My video out in preferences is set to none.

Sound works perfectly in all other apps.

I've repaired disk permissions and everything else I can

think of.

Any ideas.

Thanks.

david