Thanks for the help. I got it in tune, tightened up the locks, and as soon as I used the trem bar, it was out of tune again. Apparently the guys at the shop had been using it as a practice guitar, and they replaced the locking nuts, but with the wrong size! I've gotta get them to replace it or something, I don't have another $30 to drop on a nut assembly.
Oh well, I still think I got a pretty good deal on the guitar, it's really my dream, I couldn't really ask for anything better. (Ok, well I could. But this has all the features I want now, so it doesn't matter)