Ah, so have the HTPC set up to connect to two inputs on the Denon. One for the movies etc. and one for just the music using SPDIF.
Brilliant. I have no idea why I didn't think of that simple and obvious solution.
I used extended display because when I ran "duplicate display," it ran into all sorts of resolution issues since the native resolution on the monitor and projector were different.
Since I got such a quick and easy response to this problem, here's another question (if I don't get a response I'll put it in a separate thread).
Suddenly and without explanation, Windows Media Center will no longer play my recorded TV programs. When I start playing the program (I had watched half of it last week and so know it worked), there is no sound and after stuttering for a few minutes, it gives me an error saying "Video Error: Files needed to display video are not installed or not working correctly. Please restart Media Center and or restart the computer" Anyone seen this behavior before?