After watching a recorded program, I tried to go back to the list of recorded programs and I was surprised to find that the whole list was gone. I tried various things to get the list back, and finally I did a restart of the Tivo. After the restart the recorded program did reappear. I was wondering if this behavior is a cause for alarm, or if it is a simple hiccup? Is there something else I should do to prevent this from happening in the future? It is the first time this has happened in several years of use.