I'm at the end of my tether with this one

My PC was running fine , 2 ide hd's . I installed a new 3.46 socket 478 HT cpu and 2 new 1.5 gib sata drives on a P4VM800 mobo . Reinstalled windows and swapped some very nice home theatre speakers for some camera equipment . I started to run my 5.1 genius soundmaker soundcard through my stereo . All was well . Due to a corrupted admin acc in my windows ntfs system i transferred the acc to a new admin acc and the problems started . The sound , sometimes not always , first noticed when trying to play a dvd reverbed , totally unlistenable to .

I've removed a suspected faulty dvd rw , reformatted the o/s drive , updated everything , removed the archaic soundcard , installed directx and k-lite - installed the correct onboard sound driver for my mobo ( whql signed ) and still get reverb . The 2 dvd rw's were on seperate ide , correctly set as master / slave , I've tried the sound on all acceleration settings , different volume settings , I've checked for hardware conflicts - everything says working properly .

Anybody with any ideas ?

My PC runs :

P4 Prescott 3.46 HT cpu
P4VM800 mobo
600w Raw PSU
1.5 gib ram
20x Lightscribe DL dvd rw
Radeon X1650 pro GFX

O/S - winxp build 2600 SP2 fully updated .