on my RCA DVR the menu selections are as follows:
DIRECTV Central (the blue screen) > Messages and Setup > Restart or Reset System
{choices are as follows}
Restart the DVR. Shuts down the DVR and starts it up again. It will not affect recorded programs, Season Pass items, WishList searches, or TiVo Suggestions.
Reset Thumb Ratings and Suggestions. Removes all Thumb ratings and deletes the list of TiVo Suggestions under Pick Programs to Record. It does not delete TiVo Suggestions that have been recorded and are in the Now Playing List.
Clear Program Data and To Do List. Clears all program information, cancels all Season Pass items and everything in the To Do List, and removes all Thumb ratings. It does not delete programs in the Now Playing List. The DVR acquires new program guide data from the Satellite, over the next one to two days. Completing this process may take over an hour.
Clear and delete everything. Clears all Season Pass items, WishList searches, Thumb ratings, TiVo Suggestions and Now Playing List recordings, program information, and the To Do List and setup information, including the Channels You Receive and Favorite Channels lists. It also clears the current password and resets Parental Controls to the factory specified default. Completing this process may take over an hour.
Slacker suggested you try the last option.