Scott,

If it helps any, I seem to get this error almost every time I play a CD in my DVD player (Pioneer DV-C503) hooked into the DVD input of the 990 (audio via optical digital connection). I will switch to upsample mode when listening to the CD through the DVD player. If I change to a DVD in the player (it's a 5-disc unit) I will almost always lose the front L/R channels.

I do not get this issue if I listen to music through the CD player (Denon DCM-380) hooked to the CD input of the 990 (audio via coaxial digital connection), but it is constantly set to the upsample mode so I believe that is why.

Now that I think about my post above, just cycling through the DD/DTS modes may not pull it back. Changing the input source and then going back to the DVD input always does though.

If I can help you any further with this, let me know.