[SOLVED] Strange problem with PHP Code plugin widget

Juggledad, any idea on this one? I had the PHP Code plugin working, and had a widget in the right sidebar to show a different real estate image each day. It was fine, but I was trying to figure out what was causing the site to be so slow, so I was deactivating plugins one by one. When I deactivated that one, I started seeing this in the right sidebar where the ad used to be: I reactivated the plugin, and the ad is now showing up again as before, but so is this error message. I've dumped my browser cache but it is still there. Help!?