Alright everyone, here's the answer, or at least one of them. Prior to now I had a SoundBlaster PCI. I'd upgraded EVERYTHING except the motherboard and processor over the last two years. The only problem I had was when I started the game, it would only play if sound was disabled, which allowed it to play perfectly, but without sound.
Today I stopped by Best Buy and picked up a SoundBlaster Audigy 2 Value. I popped it in, loaded the drivers, and it works perfectly. KOTOR2 works 100%. I find it to be absolute trash that I had to upgrade to get this game working, but it works, and I have an upgrade I wanted anyways, not bad for 70 bucks with a 20 mail-in rebate.
So there you go. If it's been a long while since you upgraded your sound card, expect that to be Obsidian's next fix...
--Princess Chibi