I'm sure you checked this or it was suggested but I will say it anyway...

When looking at the display on the 1050 are you seeing more than your two front speakers showing as being "on"? My only guess is that you have the 5, 5.1 or 6.1 configured and when nothing is being sent to your two speakers the sound is "dropping out", but in reality is be sent to missing speakers.

Make sense? If you have already tried that... don't have another bit of advice at the moment.

Larry