Why has my Firefox quit working?

[irb]

* Quoth Jason Spatafore (jason_online at spatafore.net), on Sat, 2009.11.07, at 15:08 -0700:
> Drop to a command line and type links www.google.com
> 
> Is that working?

And, while you're there, try running Firefox in Safe Mode:

firefox -safe-mode

If that works, then it's could be that you've got a problem with your
extensions. You might try re-enabling them one by one. If it doesn't work,
then try re-installing the package.

Any other URLs work?

/i.