Here is one to report. First off I believe that the problem is a heat related problem, and there may be no issue with the 721. My wife shut off the AC today in the bedroom, and the temps are in the mid 90's. When I came home I sat down in front of the 721 and hit Guide. There was nothing I wanted to watch so I pressed guide. The PIP window in the top right portion of the screen did not go to full size, so I had a black screen except for the picture in the corner. By pressing guide and selecting another channel the 721 went full full screen again. Then later, I turned on a movie on Showtime. My phone rang so I hit the pause button, when I was done with my call I unpaused the screen the video played however no audio. If I switched to the second tuner audio was fine but on tuner 1 the audio was off. I turned the power off on the remote and then the unit would not power back on (while the power light came on there was nothing on the screen) I went up to the unit and held the power button down untill the unit rebooted itself. Once the unit came back up everything was fine. Again not a bug to report however lets hope this is not a common occourance.