Now my browser crashes about twice an hour,
That's funny, I've found that Firefox 3 is *more* stable than any other browser I've used, including IE and previous versions of Firefox. At this point, I'd be suspicious that there's either (a) something else going wrong with the system, or (b) it's a specific web site or a specific third-party extension that's making it crash. What extensions (if any) are you running?
and their trick of changing my default download location without telling me where the files were going proved to be endlessly entertaining.
I never ran into this problem. It's always downloaded to exactly where I tell it to download. Very strange!