I recently sold a PVR 921 to a guy and he said he was unable to activate it because it was not MPEG4 compliant. As far as I knew, I thought Dish wasn't going to MPEG4 until the end of the year and even then they were grandfathering existing HD receiver owners for a period of time. I called Dish and they said this was incorrect - that they even issue new 921s. Does anyone know who's right???