After an update of my Ubuntu 8.10 (Intrepid Ibex) my Firefox didn’t want to start anymore.
This is what the command line returned after I started Firefox in there:
Could not find compatible GRE between version 18.104.22.168 and 1.9.0.*.
The solution for the problem was quite simple. This line made Firefox work again:
sudo xulrunner-1.9 --register-global