Comment 13 for bug 677815

It was working when running firefox-4.0 from ubuntu-mozilla-daily/ppa which has the betas and nightlies, and quit working with mozillateam/firefox-stable which has the final firefox 4. This is because the language packs are in /usr/lib/firefox-addons/extensions/ and not /usr/lib/firefox-4.0-addons/extensions/ .

Here is a workaround: `firefox -uilocale en`, go to the addons manager, open the language pack pane, disable language packs.

I filed a bug over there: https://bugzilla.mozilla.org/show_bug.cgi?id=644933