There are currently several sites I visit regularly -- as part of work, mind, so these are professional business sites not bleeding edge web geek blogs -- that will crash Firefox.
Have you filed bug reports for those crashes? Care to share more information about the websites that cause them?
I'm serious, I can try to help get those bugs resolved.
When a fellow says, "It ain't the money but the principle of the thing," it's the money. -- Kim Hubbard