My cards seem to have been FAT16 by default. I have not had to reformat anything, in fact I have several times taken CF's out of cameras and stuck them in to copy files over and it worked fine. The one I have in now is one I used to use in my camera (generic 128MB), and I play MP3's on it fine. I have had problems with SanDisk SD Cards (see
http://www.aximusers.com/forum/index.php?a...t=0&#entry4773).
It may be a card problem, unless someone has any pearls of wisdom.