I do not have a 7.1 system, only a 5.1. I can try plugging the rear speakers into side, but that wouldn't explain the lack of center sound..? (and missing sub)
also, I forgot to mention that I have Windows 7 Professional 64 bit.
I am waiting for new graphics cards, as my old ones are DX10 (if that might make a difference? The Realtek manager detects my system as DX11 [probably because of Win7]. A pair in CrossfireX, Radeon HD 3850) My CPU is Phenom II x6 1090t @ 3.21 GHz. 16 GB corsair DDR 3 ram (not overclocked, so 1333?)