No more global installation مقيمة بـ 3 من 5 نجوم
I like this extension.
But since TB 3.1 it can no longer be installed as global extension (see http://kb.mozillazine.org/Installing_extensions#Global_installation). TB reports it as 'incompatible' with this version (tried TB 5, 6 and 7).
Single-user Installation works!?
Support for global installation is something that was removed from Thunderbird, Firefox etc (i.e. gecko). It is not something that can be affected by this extension.