I was reading a couple of the suggestions people had on the other board. sorry I didn't post there but I'm at work and haven't had time to register over there yet.
I think having the background volume change when another sound activates is possibly a bad idea. If the background music changes volume everytime you select a game because it has a sound associated with it, it's gonna constantly fade in and out. If you were to implement that, I would suggest a way to turn it off. Just my $.02
-G