I'm using it on a Mac and Ctrl+Click doesn't work. Can you please change it to command+click or something ? Its great to lock the sort, but its a pain not having a quick way to sort. Thanks for the great addon anyway.
When I updated Thunderbird to rel.5.0 I discovered that the add-on was "killing" the status bar text, with the POP traffic and the "contents" of the active links in the messages (dangerous!) But an e-mail to Janek was enough to get - in few days - a new version fully working again. In the meantime I worked without the add-on and REALLY I realized how much I missed it! A really MUST-HAVE add-on! Fine Job, Janek!