I have had a Roamio for about a month and twice in the last 2 or 3 weeks, I have turned on the TV/receiver and there is no sound coming from the speakers. I tried restarting the receiver, switching back and forth between Dolby and PCM on the Tivo and still no sound. The first time it happened I unplugged the Tivo and restarted it and that fixed it. This time I tried putting the Tivo in standby and the switching back to to live TV and the sound came back. I don't want to have to keep doing that every few weeks. How can this be permanently fixed?