Rated 5 out of 5 stars

Never mind, it suddenly started working in T-bird again... might have been a problem with another extension.

This review is for a previous version of the add-on (1.3.20110715). 

Cool, thanks for the update.
I got around to trying it with Thunderbird 5 (both Linux & Windows) and had no problems, so I was confused by your initial report.
Glad it's resolved itself!

Rated 4 out of 5 stars

I love the extension, but I just updated to T-Bird 5 and it doesn't seem to work - it shows in the status- or tool-bar, and I can get into the configuration, but nothing happens on mouse-over or when I click the icon. :(

Is there a fix, or should I just give up and install it in FF instead?

This review is for a previous version of the add-on (1.3.20110715).