I recently bought a new SanDisk Cruzer U3 drive primarily to move music files, but for other items as well. I own a MacBook Pro. First time I used it it had the full 8gb (minus space for obvious drivers). A friend uploaded 4gb of music and when I got it back and moved everything onto my comp, I still only had about 4gb left. After deleting her files, it didn’t reset to 8. I put files on it, and now I have less than 1gb remaining and can’t add anything onto it anymore. There are two empty folders and nothing else, but still have 840 or so mb. Why is this and how can I get back to orinigal state? Thank you.