If a flash drive is empty (256MB), but reads full when you try to move a file into it, how do you fix that? I have two students with empty ones yet they can't transfer any files to them. Would it be from deleting files that were on them while they were in another computer, but not emptying that trash before ejecting the disk? I found that mine would read as partially full unless I emptied the trash in the same location where I deleted the files. Is there any other way to deal with this issue that I am not aware of?