nor sound from audio cds - RH7.3

Well, I managed to install Via's audio driver for my new PC, and RH 7.3 seems 
to be making all the right noises now. However, when I insert an audio CD in 
the drive and begin to play, it doesn't make a sound.

Cables are all connected (plays okay under windows), and the mixer has the 
correct settings (cd selected and no muted).

I had a feeling there was a small bug in RH 7.3 that affected audio cds(??).

Can someone let me know how to fix this (it was working before the reinstall).

Cheers,

Lloyd