Visual editor menu missing, displaying html code

When I upgraded from 2.7.1 to 2.8, I found that there is no menu on the visual editor. Additionally, when I switch back and forth between the visual and html editors, the code from the html editor appears on the page for the visual editor.

There’s a picture of exactly what I’m talking about here.

That is the visual editor.

My Flash is up to date, and I’ve messed with all the plugins. It’s possible that I’m a complete idiot, but does anyone have any suggestions?

Bueller?