Really odd issue with eqtheme.mp3

[ChaosSlayer]

i have a related issue.
i have replaced eq theme music mp3 with eq2 theme music mp3 - all works fine

BUT i have tried to replace combat music with soem other mp3 files- they work. so do any other mp3 files BUT after that all the old XMI music breaks and only produces SHHHHHHHHHHH - noise from the speakers

i can't figure out why repalcing an mp3 with mp3 would have any affect on xmi files I am not even touching

[ChaosSlayer]

ok apparently replacing mp3 is not the cause of xmi music screw up.
my xmis just not playing or something.
I can ALMOST hear in the speakers the static noise which sounds like approapriate xmi is playing but sound is garbled into static.

I bet this is some sort of sound driver related screw up. But its been working for a long time and all other sound file types play just fine, any ideas on a quick fix without having to go into al the troubles like blindly reinstalling EQ/drivers? Anyone knows for sure how to fix this?