My mother recently complained to me about a memory stick. She was trying to copy some photos on to it, but after a while, it just stopped saying “out of space”. So she took a look at it and found about 1.5Gb of free space. Weird.
Eventually, when I ended up looking at it, the first thing I noticed was how many files were on it. 512 exactly. A suspiciously round number. And when I fired up Disk Utility, it confirmed my suspicions: the memory stick was formatted with FAT16, which only allows 512 entries in the root directory. Thank you very much, you fool of a manufacturer.
Anyway, reformatting it with Disk Utility managed to turn it into a FAT32 filesystem with suitably larger limitations.
Actually, before I spread too much blame, it may be down to some weird licensing arrangement.