Pressing record in middle of tv show etc

I remember being able to record a program from the beginning after it had started, if it had been the current channel for the entire time.  Now a recording is only from the incoming signal.

I record sporting events and watch them delayed to avoid commercials.  (I rarely watch anything live for that reason.  With all the breaks, that's the best way to watch the Olympics, particularly if it's not live anyway).  if it's an early game that I really don't want to miss, I may change settings the night before to set that channel as the power on channel a half hour before game time.  I usually start watching a recorded game 20-30 minutes after the game started.  That's usually enough time to allow me to skip commercials (and halftime for football) for the entire game.  However, if the game failed to record for any reason, the start of the game is still in the buffer because that was the power on channel I selected.  (Contour 1 buffers an hour.  It may only be 30 minutes for Contour 2).  I start a recording from that point and reverse the buffer to the start of the game.  I then watch the game from the start until where I began recording.  I can either continue watching or watch later from when recording began.