I’ve worked out why I can’t use AjaxLife at school.

You have attempted to access the following web page:

http://static.ajaxlife.net/AjaxLife.Libs.IE6.js

Access has been blocked because:
Page content filters applied - score = 7576

Since this file contains only prototype.js, scriptaculous and ExtJS, I haven’t a clue why it’s been blocked. It is annoying, however.