Damn it! My computer is in such an awkward position that hooking it up to the TV will be almost impossible (you'd have to see the layout of my room to understand). However, my PC doesn't seem to have a 1366x768 mode*, anyway, and I'm not sure how to adjust the PAR on my computer. I honestly don't see why it would kill them to make disabling the overscan an option on the normal user menu. I sent an e-mail to Vizio's tech support to see if they can tell me how to open the service menu. I haven't received a response, yet.

*I just did the math. Wouldn't 1365x768 be closer to the 16:9 aspect ratio of the TV? Just a little nitpick.