Why doesn't TiVo pad suggestions?

I recently started letting my Tivo record suggestions. I was watching a BBT episode and it cut off just after the last segment started. I checked and it recorded a 30 minute slot for the show. Looking at other suggestions, they were all for exactly the time slot of the programs in the guide.



This may work for most movies, but as we all know, not necessarily for sitcoms.



Why don't the default recording options also cover suggestions?