I recorded the season premier of House on my Tivo. Unfortunately due to conflicts I only had it recorded on one of my Tivos. The recording shows an hour recorded but when I go to play it, it gives me the message Error playing a recording. According to the message there was no video signal to the channel but Bones recorded fine on my other Tivo. This is on an unmodified RCA DVR120. Is this a sign of hard drive failure? Anyone dealt with this before?