I'm glad to be of help! In retrospect I should have started a new topic rather than hijacking this one; I don't anticipate you'll have any problems, but if you do feel free to start a new thread. In the meantime, enjoy your 7.1 :-)
Okay, so if anybody else is having trouble with getting 3d audio (quad, 4.1, 5.1, 7.1 etc) working in SS2, I can happily report that IndirectSound does fix it! It works flawlessly for me, all my channels are working like they should. Just make sure you don't have your audio channels set too high, that's why mine wasn't working right away. They were set at 48 by default. I changed that to 8 after JonPol messaged me to give me personalized support! How cool is that!? +1 JonPol!
IndirectSound is awesome!