How old is your HR10-250? If it's still covered by its one year warranty, have it replaced.
But first check a couple of things ....
* Be sure it's not overheating. Check its internal temperature under "Messages & Setup" -> "System Information". If it's over 50-degC, it might be overheating.
* Verify that your AC power isn't "glitching". A good quality 350VA UPS will isolate your Tivo from AC power problems and even power your Tivo for nearly an hour during a total blackout.