I am using Ubuntu 12.04 with Firefox 19, "global menu bar integration 3.7.2" extension has been installed and enabled. Unfortunately the global menu integration does not work, there is still the classical Firefox menu appearing.
I have tried disabling and re-enabling, or even
sudo apt-get --purge remove firefox-globalmenu && sudo apt-get install firefox-globalmenu which has been suggested in similar cases. Any other suggestion would be welcome