Rated 5 out of 5 stars
Thunderbird 9 has this feature built-in, right click on the menu bar and uncheck it.
This add-on is no longer needed, thanks to the author for providing as an workaround so far.
Rated 3 out of 5 stars
Why has support for Thunderbird been dropped? Please consider adding it back so we don't have to hack the version support in older versions which still work in Thunderbird 6.This review is for a previous version of the add-on (4.0.20110415.1-signed).