Sony E280 HDMI input - Stereo Only (2 Channels)

[xithus]

Hi.

I'm using this Home Cinema System with a PC. I've plugged a HDMI cable from my nvidia Graphics card into the HDMI in on the System and ran another HDMI Cable to my PC Monitor. My issue is that is that the Audio Playback is only working on 2 channels. I get 5.1 if I play something with Dolby Digital but everything else is only stereo and windows sound manager is reporting that the system is capable of 2 Channels PCM, Dolby Digital and DTS.

I've done some googling and it's seems to be a tough one to sort, some forums are reporting that the EDID (i'm not entirely certain what that is) may be incorrect on the surround system and reporting that it is only capable of 2 channels. Apparently this can be edited but I'm not sure.

I've attached a picture of what Windows is telling me.

Any suggestions on what I could try would be appreciated, thanks.