This has happened to me about a dozen times now: every once in a blue moon I'll load the Stack Overflow homepage, and Firefox will crash. It's happened enough times, that I'm pretty sure that it has something to do with SO.
The following is the only error found in the error console, but the error console seems to only be recording events after the fact.
Timestamp: 11/19/2012 4:27:15 PM Error: no element found Source File: http://stackoverflow.com/posts/13463336/ivc/5ca6?_=1353364035068 Line: 1
I'm running Firefox 16.0.2
update: it's happened two more times since this post, and and also happened when visiting the meta homepage.
It just happened once today with firefox v17.0.1