I have a Sony STR-DH520 Theater Receiver, and I'm running AV from my GTX 580 through an HDMI cable. Video works fine, but when I try to enable audio it says that the device is not plugged in. When I connect it to my Alienware M18X's HDMI in everything works fine, so it's not an issue with the card. I have tried updating the HDMI audio drivers from nVidia, but I get a .dll error.
Does anyone have any experience with this that could help me?