Use Support Site link for newest version Rated 5 out of 5 stars

If you are not able to install this from Mozilla, try the Support Link to install latest version. It's at least compatible with FF 10.

http://yellow5.us/firefox/osb/

Firefox 6 compatible update Rated 5 out of 5 stars

Here is the link to the latest update compatible for FF6.

Organize Status Bar 0.6.5
http://yellow5.us/firefox/osb/