I'm trying to use my 4th generation 16g iPod Nano as a flash drive. I know how to set it up, and I've done it before, but now I'm having trouble. I restored it so I no longer have anything on the iPod, leaving 15g free. The file I'm trying to copy to it is 4.18g and when I attempt to copy it, the iPod says it doesn't have enough room regardless of the fact that there is 15g free. Anyone know how to fix this?