USB stick/ mac problem

edited, just realise the problem has been fixed, doh, either way I'll just leave that out for other who may run into similar problem.

Had the same. Even though deleted all files off of the USB stick it still said it was full.
Geezer in the shop said that the stick was 'fucked' (some sort of technical term) and there was nothing to do but throw it away and buy a new one. He wasn't trying to flog one as he didn't have a big enough stick (ooh er).

always happen with Mac (for some odd reason), just simply go to

Application - Utilities - Disk Utility, then click on the USB disk on the menu (not shown in screenshot).

make sure (FAT) is chosen for being able to use it between Windows and Mac, and press erase.

that's all there to it.