Well for the sake of anyone finding this thread via search or Google I figure I'd let you all know the outcome, which I am sure you are all dying to know....
In the end I returned the Nvidia 210 card and picked up an ATI Radeon 4350 and it works in Ubuntu with the ATI proprietary drivers out of the box, including Audio over HDMI. So now my Ubuntu HTPC and MythTV box is boasting 7.1 audio out to my receiver, and life is now good....
Well I spoke too soon. The audio out works, yes, and my receiver does get surround sound. However, I cannot control the audio levels via software mixer in Linux. So I need to figure out how to tweak that.