Personally I use Quick-Punch record mode instead. Much easier - and no faffing around with putting/remove pre-rolls.
The great thing about it, is that even if you miss the first second of the punch it, it actually records from the moment you press play.
Basically, you press play, until you get to the punch-in point, at which time you press record (for this I use number 3 on the number pad) - and it starts to record.
otherwise, you can you pre-roll to do this. Open you the transport dialogue, and select the number of bars of pre roll you want and make sure the words "pro-roll" are highlighted. You should now see a little green flag on the timeline before your playback head - this is your preroll. So you press play, it'll play the number of pre-roll bars you've chosen, then drop in to record mode.