Ok, I did a lot of searching, and I found the problem (the uTorrent FAQ had my problem listed, but none of their solutions helped). The problem was that my file was "being accessed by another program", so I downloaded this program called Unlocker (http://ccollomb.free.fr/unlocker/), and if you're getting this error message anywhere, you just right click on the file, go to "unlock" and a list will come up, so select "unlock all", and my uTorrent magically works. I have no idea what it actually did, but it's the only solution that worked.