This has happened twice when watching a tv channel in dolby digital 5.1 and change to something in stereo theirs no sound if I go back to the 5.1 channel its fine go back to the channel in stero no sound. So I turned receiver off and back on and it fixed it. About two weeks went by and it happened again. Has anyone else had this happen? Also when this happened I put it on the radio had no sound.But turning receiver off and back on fixed it.