Sansa Clip has tons of room but says FILLED and won't sync...HELP!

Had the clip for a few months and I love it, I haven’t done anything crazy to it & all the firmware updates are in place. I keep trying to sync it like old times but it just won’t work! I’ve got 3GB free, but it refuses to update at all! Any suggestions? Someone said it meant a virus, and if that’s the case then what do I do?



Update----it just DELETED everything for no apparent reason. Anything?