I have this entirely weird issue, which i believe is caused by my Brand new board i got two weeks ago...
Out of the onboard sound i cant produce my subwoofer channel, the center works, but no sub... so i thought id try my old audigy in it, same issue... I tried my logitch X-540 set on my other pc, works perfect still, this isn't/can't be a software issue in my eyes either, i formated to xp twice with the same problem, and now im running x64 vista.
Board: GA-MA780G-UD3H (rev .1.0)
Processor: AMD Athlon x2 4050e 2.1 dual core 1MB cache
Ram: 6gb dual channeled DDR2
Video Card: 9600GT 512mb
HDD: 150gb Raptor, 250gb Wd, and a 500gb Wd Mybook