sometimes if I am watching a show and decide to record, if I was on that channel prior to the show it will include the previous show due to the buffer and a 30 min show will record 45 mins or so depending on how long I was on the previous program. My question is why does this happen only sometimes and other times it does not? I have sometimes decided to hit record and the tivo erases the buffer and records the show, and I may have wanted to include the previous show (buffered) portion. There seems to be no real rule.... anyone have this issue? Using my series 3.