I cannot say for Windows at this point, but the new Mac version of Firefox 2.0 has crashed on me 5 times or so in the last 24 hours during normal use. While the recovery of a session with tabs compensates for this slightly, it does not bring back, for example, the text in the box in which I am typing this. I almost lost a gmail as well were it not for gmail's excellent autosave draft feature.
Indeed, I did lose a nice post I wrote yesterday in Spanish concerning Bush's backstabbing of North Americans with his signing of an order to build the Wall. The thrust was that his alleged pro-immigration position was the last shred of dignity the man had left which he has now utterly demolished.
Back to Firefox, I approve of the built in spell checker, which mostly eliminates my need for the google toolbar plugin.