UD,
Fostex has it set up so that you don't waste any of your time for recording.. When you record a track it only records when you're playing, and doesn't record when you're not.. Your first track could be a full 3 minutes long, and you're second may only total out to be 30 seconds or so, but even if you start recording from the very begining that track will only contain the 30 seconds you played and not a full 3 minutes so yes if some of your tracks are shorter you can get longer recording time per track..

Squeak