The Mozilla Foundation released version 1.5.0.1 of Firefox here. I looked at the release notes before downloading to see if there had been a fix for that bug which causes pages apparently to spontaneously reload, which affects the Mac version and causes the loss of any data you have entered into any web page like, say, your Movable Type blogging interface, since the last reload, and there wasn't. I downloaded it, started using it, and lo and behold, it did spontaneously reload an MT composition page on me. That's the last time I use that app for any serious use until they get that problem fixed. Not sure if it affects Linux or Windows.
(Tag: Firefox)
Sounds like an awful experience. I used the IE7 Developer Beta today. Its pretty cool.
IE7 apparently has quite a few security bugs already. The security community has started warning IE7 beta testers :p