I usually don't use the editor feature in WP, but needed to use it the other day and was surprised to find that clicking the Update button after editing a file take me to the home page on the front-end of the site! Strange!
I verified this behavior is FF3, IE7/8, and Chrome. Not only does it take me to the home page, but it also doesn't save my edits. Looks to me like a mis-coded submit button on the editor.
Hope you can fix this for 3.0.1 :)