Rated 5 out of 5 stars

Snakiej and all who has compatibility problem, here is a little trick:
Open application.ini file in the thunderbird folder, and change Version=3.0 to Version=3.0a2pre or Version=3.0a, or even Version=2.0, or any version you want. Then save it, and restart thunderbird.

It works with all addons. :)

I like this addon very much, my favorite feature is, that I can set up to see my contacts' another email addresses in the sidebar, not only the default.

The only problem is, it doesn't work with portable thunderbird