Displayport S/PDIF Issues Please Help


Jul 23, 2009
Hello, I just built a new computer, with a ASUS P6t Deluxe V2 motherboard and a Nvidia Quadro fx 3800 graphics card. I ran an hdmi cord (plugged into the quadro with a displayport/hdmi converter) to my Sony receiver. My Quadro is fed audio through a S/PDIF cable from my motherboard. It sends 2 channel audio to my receiver just fine. I would like it to send surround. In the windows HDMI audio out configure settings it has the "surround speakers" check box faded so that I cannot click. I was hoping anyone could help explain why.
Any help is appreciated.
Thanks, Cory