My 921 keeps giving me satellite signal loss errors. I tried to watch USA Network this afternoon, but my receiver would not lock into the station. I checked my 501 and USA was working fine. I called Tech Support, and they had me do the usual... Check Switch, Power Button Reset, and A Power Cord Reset. Nothing worked. They wanted to replace the receiver, but why, I see a 622 in the near future. Anybody have any other suggestions.