I'm not sure what changed.  FireFox used to be one of the most stable browsers I'd ever used.  However, since the upgrade to the 3.x track I've had nothing but problems.  The browser is still functionally great, but the stability has taken a nose-dive.  I've had crashes and lockups on both XP and Vista and despite getting the latest updates and fixes in both environments, the problems continue.  I'd switch to Chrome if it weren't for concerns over security vulnerabilities.  It's a new browser that's still in beta so I'm not surprised there are a few kinks to iron out; but I'd rather not be the guinea pig that finds the problems.

So for now, I guess it's back to IE.  *sigh*