After much button pushing I think that my receiver is not working properly.
With multiple outputs to test, my pc audio drivers perform consitantly. If I select an audio out source before starting the cd, It will switch to the appropriate output. I could switch back and forth between Display audio (HDMI) and analog audio just fine. When I switch to the activated digital out, the receiver sees nothing. It seems reasonable to assume that since the other two outputs work as expected that the digital out is working as well.
Darn. When I picked up this receiver cheap all I wanted it for was to drive M80s for two channel. Its doing that just fine. I didn't expect to have the funds for a full system so quickly.
Looks like my next option is to do 5.1 analog out from the computer and use the receiver strictly as an amp until I have the funds for a proper receiver.
I still havn't reproduced that weird cave effect again.
