I have noticed I am missing the end of some of my recordings but have a couple of minutes of recording at the beginning that is either adverts or the earlier program that was on.
Is there anyway to get the TiVo time to sync with the tv show times. I know I can extend the record time but this is no help when I am recording lots of shows one after the other.
This is almost certainly caused by poor time-keeping by the broadcasters, particularly the BBC.
The only thing you can do is use the padding before and after each program to resolve this.
Agreed with Ernie, this is almost certainly programs just running early or late, and padding is the best way to deal with this.
I'd also make sure your overlap protection is set to "reschedule recordings rather than cut them short" and let TiVo reschedule the oft-repeated programs for you.