Okay, I got a message saying that FireFox 3.0.6 had downloaded and that I needed to restart my browser for the changes to take effect ... BUT, I was in the middle of doing something and decided to finish up before going through with the update.
Just my luck, my browser crashed, so when I start it back up I go to "Check for Updates" under the "Tools" menu (because it still says I'm using FireFox 3.0.5) and it says to "download and install" 3.0.6 ... So, even though it had already downloaded the newest version, I click "Okay" and now it's just been sitting on "Connecting to update server" for the last half-hour with no movement whatsoever.
Is this a case of ignoring the problem until it goes away (i.e. finishes downloading a second time), or does it call for something more drastic?
EDIT: And of course, it's telling me "Apply Downloaded Update Now", so this thread was a giant waste of time ... mods please feel free to delete it from existence.