I think I've figured out what the problem is.
I created a new firefox profile. I was using the store password option and for some reason that seems to make it crash.
Scratch that, even without that, when I login, It just seems to crash it.
It's not the cache...i've had to redo my entire windows profile because of a separate issue so i don't think there is even any cache to delete.
Hmmmm I'll keep trying to figure out what it is but until then...anyone thinking about upgrading their firefox, hold tight for now, unless you want to want to go ahead and do it and confirm for me that it is a general problem with firefox and not just with me.
Either way, I'll try the same on my home pc today to find out if it is Firefox.