I have an HR21-100 (black box) connected via HDMI to my Marantz SR7001 receiver. As of yesterday, every channel, including recorded programs, drops audio every few seconds. I can see on my Marantz that the PCM indicator comes on and off when this happens. HDMI sync issue? I did manage to watch a whole 30 minute recorded episode of Clone Wars in full 5.1 Dolby Digital without issues, but I think it was a fluke. I have native mode off, and dolby digital off. I've tried every combination of resolutions, and this is driving me (and more importantly, my wife) bonkers. Why would this suddenly start happening?