My premier Tivo is starting to not record some shows. It is random in terms of channels. This week it did't record the first 15 minutes of NBC hd news and then kicked in. When it doesn't record there is no signal or picture on the channel. But if I go into the signal monitor, which involves turning off the recording and then seeing the monitor,the signal will suddenly come in. The signal leval is about 80 and the s/n is 35 . This happened with my tivo HD recorder when I previously used it . It sounds like a design defect. I would like Tivo engineering to look at this problem.