Here's a tip for newbies.
Let's say you are watching the Super Bowl live but you are only planning to record Grey's Anatomy. You see that the game is running over. Here's what you can do.
Timeslot starts at HH:15 but let's say the game actually runs to HH:30. If GA's has not started already, and you are extremely tight on space, stop the recorder before GA starts and dump the buffer by quickly changing channels during a commercial break. Then start recording again (press the record button) before GA begins.
Or, if you are watching the game behind live and GA has already started, proceed to the next step:
Find out how long the game ran (let's say 15 minutes over) and go into the Now Playing List. Choose "Change Recording Options". As long as your TiVo is still recording GA, you can pad an extra 15 minutes (or more) to make sure that the entire show is in one unbroken recording.
Jan