My UI is hosed... Two identical users logged in, etc. Help

Anybody ever seen anything like this? Leopard's window manager seems to have gone crazy and I'm seeing weird things in my menus (like the apparent hotkeys for my user accounts in every menu twice...) There are extra black boxes around things like the red close button in windows and around documents on the desktop and in pretty much every window somewhere, but I don't know why this is happening.

A restart hasn't fixed this and force quitting finder and restarting it doesn't seem to do anything either.

I feel like this might be somehow connected to iTunes 8, as I had a kernal panic almost immediately after installing it (from disconnecting a shuffle from the USB port) and since then, besides some light iWorks use and whatnot, there's not much I've really done on my computer. It started this morning and I'm sort of at a loss, since I've never seen anything like this before.

Any ideas?

 

While I was verifying permissions, the strange behavior just disappeared after it had been happening all morning.

Hopefully it won't return. =/