I have a creative x-fi extrememusic sound card in the computer and a denon 2807. I'm trying to set it up so I can have surround sound from the computer to the living room speakers set up with the 2807. I bought a digital I/O module from creative and tried to connect via optical to the receiver, but when I go to the speaker setup and try to make the center, or surrounds play, it only comes out of the front left and right. Is there some setting I don't have right or do I need something else to be able to connect it correctly and get 5.1?