Terrible sound with RealTek

[mal]

I have a machine with a RealTek HDA Azalia ( is that how you spell it ? )
and the sound is terrible ...on some applications

If I put a CD in and play it using CD Player it's all distorted - if I 
rip the CD and play the ogg
files with Helix it's fine.  Xine is also distorted

The 'pling' sound that plays to test the sound card either during 
install or later using the
sound card detection sounds perfect

It sounds as if I have turned the input right down and then turned the  
output right up so it
sounds 'crackly and clipped '  if that makes sense

Also Helix plays loud but CD Player is really quiet so I have to turn 
the speaker volume up

any thoughts

thanks

mal