Ok thanks, I thought I remember reading somewhere that you to have to press the blue button to switch to another game before removing the card, but I can't remember where I seen it.
Is the 31 games limit related to file size? Or is it regardless of file size?
Also, I think 2 (or more) SD cards with, say, 16 games each would be an easier way of managing lots of games, pressing the blue button 30 times to get to another game seems long winded.