I have one of those flash drive usb sticks to back up documents, which I began using when I still had MS Windows. My problem: on the mac, when I right-clicked on the flash drive, it showed up as nearly full. I removed a large folder, ejected the flash drive, plugged it in again, and there showed no increase in available capacity; the numbers were exactly the same as before. When I tried putting the folder that I had just removed back onto the flash drive, a warning came up that there was insufficient capacity. But the folder had been on the flash drive not five miinutes before! So how do I make space on the flash drive? The panel that shows available space also shows something about the flash drive's format as being MS-DOS. Is that part of the problem? I'm not technically gifted, so I hope there's a solution within my grasp.