Even if I just hit the SETTINGS link in the admin panel it locks up FireFox (even the new 3b5) and I can't use any other tabs in FireFox until the page has rendered. Same happens when writing a new blog post.
I'm seriously considering finding another blog application as this is getting very annoying.
I've even tried the WordPress 'hacks' to enable longer delays in FireFox 2 just to stop it timing out and displaying the STOP SCRIPT / CONTINE buttons. It doesn't time out now, but just locks up all of FireFox until the page has rendered.