I currently have my own Tivo (and the service). My friend has recently upgraded to DVR because her Tivo unit was giving her problems...rather than toss the thing, we were wondering if I could use her Tivo in my house on another tv. Can I use it under my account? I mean I assume that people who buy used Tivo's must do this without having to buy an additional subscription right? And if not, would my friend's subscription work in my house?