I am running WP2.9.2 and I created a custom theme. It worked fine for a while, and the theme and the pages all still work.
The problem is on the admin panel, the widgets page (under appearance) does not load or display properly. The available widgets bar loads, but it does not list all the widgets inside the white area. There are only a couple random widgets shown, which just float below the widgets header section. The actual sidebar showing what widgets are currently installed and running does not appear at all. However, on the actual blog there are many widgets installed and running properly. But now I can not edit, add, or remove any widgets.
I also notice that if I click the screen options bar in the top right of the screen, that nothing happens.
I am running Windows 7 Ultimate, using both Chrome 5.0.375.86 and IE8.0. They both display the same way.