Vista DVD playback on Hyperthreading CPU

Hi,

Found frustrating situation. I have a box with Intel Pentium 4
Hyperthreading CPU, 2 audio cards (one is with the driver from Vista).
During DVD playback (tried 3 DVD players + Windows Media Player) I've been
hearing clicks that occurs in headphones or in speakers. For both audio
cards. It was when hyperthreading was on. When I have turned it off the
effect went away and it seemed more or less ok. Under XP everything was
fine. CD playback is fine for both XP and Vista.

Any suggestions?

Thanks.

--
Andrei.