Sorry if this has already been asked but I checked post and couldn't find anything. I will be getting a Tivo HD soon which is only about 160hrs Will I be able to upgrade to a larger "A" drive? I would think that would be easier since I don't think you can add a "B" drive to it. Please correct me if I'm wrong. Right now I have a Series II 80hr and I dropped another 80gb HD into it years ago and I have had no problems but I read at that time you could not change the size of "A" drive and the added drive had to be the same size.