While it appears I have a toslink, I am curious as to whether anyone has gotten 5.1 successfully from their HDMI port. I have installed the newest drivers from NVIDIA's site as well as updating all the other drivers on the computer. However, my HDMI is still outputting a stereo signal. It seems that I'm not alone but all of the threads I have seen are dead ends.
To note, under Control Panel-->Sound--->NVIDIA High Defintion Audio, it does in fact show 6 channels. This is being tested on a Pioneer Elite SC57 which can handle just about ANY input.