I have an HR20-700 that has started having a strange intermittent audio problem. Sometimes (not all the time) there is video, but no audio on BravoHD (Channel 273). This can occur on both recorded and live TV. Once it the sound drops, it doesn't come back - we have let it go for over an hour and the sound never comes back. Pausing then play doesn't fix it. Remote off doesn't fix it. However, if I change the channel, the sound comes back, and if I then go back to 273 the sound is now OK. I have not been able to figure out if it always occurs when recording and also watching live, or any other combinations. It is intermittent, but it does seem to happen at least once a day. This HR20 is connected via HDMI to the TV for video, but the audio is via optical to a Pioneer receiver. I have another HR20-700 in a different room that does NOT exhibit the same symptoms - and today I confirmed that when the audio dropped on the one unit, the other unit continued to have audio on the same channel with no issues. The "changing the channel fixes the problem" sounds familiar - I think I may have read about that somewhere. Changing the channel also dumps the buffer, and I suspect that's a clue - but I have no idea what it means. Any ideas?