So I got the receiver today and setup. Mostly works but I seem to be having problems listening to music. First some info on my setup.

I have my cable plugged in via HDMI to the TV/CBL HDMI slot
I watch movies and listen to music from my HTPC which is using the DVD HDMI slot.

I can watch tv and output sound via the receiver no problem
I can watch movies via my computer which is using MCE and TMT 3 perfectly find via my receiver.

The problem is I can't listen to music. When I play a cd via MCE or WMP I get no sound. I can't figure this out. I've tried various options but nothing seems to work.
Any ideas?