M3A-H/HDMI Sound Problem

[rudeshark]

Hey guys. I am having a problem getting sound through the HDMI connection on this mobo(graphics card to be precise 8600GT+). If i plug in the analog then no problem, set speakers as default and we're off. However when i plug in the HDMI cable(both sides) i can't get any sound at all. I have tried absolutely everything as far as configuration is concerned and my mind is beginning to fail me now.

Please advise

Cheers