The workaround in post #17 solved the problem for me (but replacing langpack-sv for langpack-fr). Using Thunderbird version 12.0.1+build1-0ubuntu0.10.04.1
(The workaround in post #5 didn't work as is, since /usr/lib/thunderbird/extensions/ isn't empty.)
The workaround in post #17 solved the problem for me (but replacing langpack-sv for langpack-fr). Using Thunderbird version 12.0.1+ build1- 0ubuntu0. 10.04.1
(The workaround in post #5 didn't work as is, since /usr/lib/ thunderbird/ extensions/ isn't empty.)