Dashboard has lost its styling

Hi. I have several WordPress sites up and running, but have never come across this issue on my other sites. When I login, my dashboard has lost all of its styling. My site appears fine (as in it appears to have no “external” issues, with the theme working fine), but the internal dashboard appears in a “raw” format.

I have installed WP e-Commerce and upgraded all of the theme files recommended, but it ran fine for some time before the dashboard corrupted. I also uninstalled some plugins, but these were inactive (therefore not being used), and should have no effect on the site. The only other thing I did was upgrade my Mac to the latest OS, but I can’t see that this would have an effect on a site hosted remotely.

I have tried a few suggestions (re-install WP, disable some other plug-ins) but so far no success in having the dashboard return to normal.

The only other unusual thing about the dashboard, is if I go to “Home”, it is saying “This widget requires JavaScript”, under the “Incoming Links”, “Plugins”, “WordPress Blog”, and “Other WordPress News” sections. Which I don’t understand, because as far as I am aware, I haven’t touched the JavaScript.

Any ideas?