I don’t have any plugins. Straight install and use. It very well could be a 7 issue since this happens on all three installs I have. The browser will first hang, then crash and restart and it asks if I want to restore my session or start new. I pretty much only go to drudge, FR, gmail and facebook. I do click news links from FR and drudge. I do not usually venture out beyond that on a regular basis. I have a few sites I frequent and that’s it. Not sure the cause. For the most part firefox has been stable. on XP I found it to be rock solid. So far on 7 though, several crashes a day. The one thing I like is I do not lose my spot when it does crash as it restores my tabs.
I like win7 BTW but it ain't perfect and needs some fixing especially, I think, in the file system and dialog boxes. Quite a few programs choke on installation when they are dealing with the file dialog and setting paths, etc, at least in my experience.
Sorry I'm not more helpful.