Yet another Firefox update...
Now we're up to version 1.0.6 which is apparently a 'stability update' (oops, what did they break)... ah, here we go, they need to “Restore API compatibility for extensions and web applications that did not work in Firefox 1.0.5.”
Go and get it :o)
http://www.mozilla.org/products/firefox/releases/1.0.6.html