I finally found a solution to the problem. By renaming /usr/lib/firefox/components/compreg.dat yelp is working now. I don't understand why. Perhaps someone who knows could enlighten us.
-- Yelp fails to launch - could not initialize gecko! https://launchpad.net/bugs/53504 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
