In seriousness though, based on the fact that the PS3 is reporting a 5.1 signal, the problem is definitely not in the encoding of the file, so that's major progress. I would look to the Denon as the possible culprit at this point. It could be set on stereo output and overriding the multichannel signal it's getting from the PS3. If you haven't already, make sure you have it set on a mode meant for 5.1 playback.

Jason

Epic 80-800: HG Cherry