No sound in play DVD or play video library

[klubar]

When I play a dvd (in cd/dvd rom) or a ripped video in video library I get the movie, but no sound. Video with audtio plays fine in Nero or Media center. I've left all the config options to system default. Any suggestions?

I'm running vista ultimate and my only additional video playback program is Nero Showtime.

[sub]

I've left all the config options to system default.

Its much better to explicitly select the audio/video decoder rather that relying on 'system default', which can give unpredictable behaviour and change easily when you install other apps on your machine.