To Boldly Go Where No Browser Has Gone Before.....
Well Red, I use the heck out of FF, and it never crashes....? This with possibly 200 tabs across 3 to 6 windows! Not to mention that I've been to "hither and yon" and other dark, dank, morally defunct URLs. (But NO P2P)
It does however spontaneously seem to generate new windows under certain circumstances. I've been trying to attribute this to "pilot error", trouble is, I can't seem to duplicate the "circumstances", so that I might learn from them. (???)
Do you have your "NoScript" working? Do you have "clear private data when exiting Firefox" checked?
Perhaps Firefox only works well in aging Emachines with "PreShot" CPUs and insufficient memory, that are still living dangerously with XP SP-2. Give it a decent home and maybe it can't stand the prosperity.
EDIT; Oh, you're running 3.6, I fear the dark fortunes of being a trailblazer may be upon you...!
EDIT 2: The download manager in FF3.xx browsers require you to serially download pages, and won't cache mutiple images, it only saves the placeholder GIF if more than a couple of pages are open.