file transfer/Compat. between ntfs/fat

I have a user on our nt4 ntfs based network. This user tranfers files regularly between win95 fat16 and nt4 desktop via the floppy drive. Now all of a sudden it does not work. He has always used the floppy to transfer files and the floppy is now only accessable on win95. I seem to recall some deatail relating to this from Microsoft but cannot seem to locate it on technet any ideas?