I seem to be having the music issues as well. basically, it's just been more and more quiet gameplay, with seemingly no background music playing hardly ever. I've been considering actually putting together a cd track to play when I run the game, because it really gets just too quiet. I do have a RealTek integrated sound system, and on another thread regarding sound issues it sounds like there may be an issue attached to RealTek users as well.
Either way, considering the many positive things that I have seen done with the game over time, this music issue is kind of surprising, being that it like can hugely impact gameplay, and may even cause people to quit eventually?