Rated 5 out of 5 stars

Starting with the excellent fixes from Alex Thomas and others, I've forked this into a new project at GitHub.com.

It's still undergoing review and will not show up in the general list, but you can get to it with the direct URL.
https://addons.mozilla.org/en-US/firefox/addon/gmail-manager-ng/

The GitHub repository is http://github.com/nedwidek/firefox-gmail-manager-ng