I double checked the bios, but only options for audio are to turn it off, so I will give up on getting sound over HDMI with this card.

I did get audio working in Boxee, which has a similar audio setup as Myth does. So once I was familiar with it in Myth, then I saw that Boxee was using the wrong device after the upgrade.

So now my wife can watch the The Daily Show and anime on Crunchyroll in bed, so I can stop playing with settings now.