Slow sound in game

[Cube]

Hi.

 

I got the Bioshock PC demo, and fiddled with the settings until everything would run smoothly. However, one thing I could never solve is the audio. The sounds seemed to play way too slow (I put subtitles on to check, they zoomed off ahead of the sound).

 

Is this due to my PC just coping with the demo, or something to with some sound settings somewhere?

 

Thanks in advance.