Crashing ‘Write’ page

When I call up the ‘Write’ page, the TinyMCE icons don’t load, the ‘Save’ and ‘Publish’ buttons constantly blink, the “Draft Saved at” time is constantly updated with the WRONG time…

…and I can’t switch to a different tab in Firefox. In IE7 it does the same thing on the page but doesn’t crash the browser.

This is an upgrade install.