Some different bugs do get fixed with every update, but most of the time you see an update it's because a security exploit was found. And rather than wait a month or 2 months like Microsoft does, the Firefox team measures how bad the security exploit is and then based on that decides whether to release an immediate update or wait til the next scheduled release of Firefox, which is usually a month or more away. This way you're protected from whatever the security problem was. And they usually group a couple of security fixes together before giving the new update. So you just don't get 1 fix per version. So it's not like: Oops, found a security bug! Let's give everyone a new version now! Uh-oh found another one. Let's give a new version again right now! Yes, it is a bit annoying to be asked to update so often but you can turn off updates if it really bothers you that much. Although of course, there's like hundreds of Mozilla people that would advise against doing that. You know, security risks, and all that stuff. ;)