Firefox crash

[Arjan Geven]

Hi all,

I'm afraid I gave my firy fox some bad food to eat, and now he's sick.
He doesn't want to give me nice internet pages anymore, or anything
else for that matter. Which doctor can help my firefox with the
necessary medication to get him up and running again?

The symptoms:
When I start firefox, in the windowbar on the bottom it says "Starting
Firefox..". Then, this message dissappears and nothing comes up. Then,
a message pops up with the warning "Error parsing XML in
chrome://(path)/browser.xul on line 1" (sorry, don't remember the
exact error message and path, but something like this).

I typed this in Google, and found only one guy with a similar problem
on a Spanish forum, which also did not seem to have a solution.

Now, all I ever used to install applications is Synaptic, but with
some additional repositories (Hoary Backports), and I'm afraid I broke
something with that. I have no idea how to revert to an older version
of Firefox, to force an overwrite of the file in question
(browser.xul) with a fresh one or if that would even fix the problem.

Can anyone tell me what would be a good way to get my firefox up and
running again? I'm not shy of the command line, but as I'm very new to
the whole Linux thing, I have no idea how to use it to get my firefox
back...

I do have Mozilla-browser installed now, and that works.
Unfortunately, the interface of this piece of software is horrible,
and I liked my firefox much more.

Thanks for your replies,
Arjan