Well, with firefox what could've been happening is that it was downloading the most recent version of Firefox, which was put out yesterday. if you notice things running abnormally slow, that's usually what's happening. and yes, rebooting would help. If it happens again, make sure "Load images for the originating site only" isn't checked under firefox prefs, under the content tab. that setting prevents third-party ads from loading but also screws up avatars and thumbs on myspace, snapfish,  gamespy, etc.