Ah. Thanks for the tip! I'll give that a try as soon as I have time to backup the contents again (to the linux box).
It's a 4Gb "no name" card, so I wasn't sure if it might be the card itself at first, but I've definitely tracked the problem to accessing it on the Mac. Hopefully this trick will fix the problem -- it would be
much more convenient for me to be able to access the iLiad via my PowerBook than to use the desktop linux/windows box in the living room where the kids tend to have the tv blaring inane comedies.