I am using my iPod classic with a macbook. I drag and dropped a bunch of files (about 20 gigs) from my pc to my iPod to transfer the files to my mac, I then deleted the files but they still seem to be there even though I can't see them as in itunes I have 20 gigs of 'other' files.

I can't format/restore my iPod as it says I have files which are in use by another program, which I don't think is true.

Any ideas?