Your Mac OS is outdated. You'll have to update your Mac to the latest version. This is because Firefox uses new features of Mac OS that is not in older versions of Mac.

This is so frustrating. I said in my original message that I do NOT want to supposedly "update" my OS to 10.5 or more. I have seen those versions and DON'T like them. They louse up iMovie & are more cumbersome. I am not interested in layers of networking, games, and being tangled up with an insecure "cloud." The iTunes set up is already obnoxious enough, when you try to manage, organize & back up your music. I do not like how the computer/phone/etc. high tech world take away our choices, forcing us to up grade to stuff we don't want, frequently at a higher cost. I am not the only one who wants to stick with the better Mac OS system. If this answer is actually from Firefox, then I am disappointed in FireFox. I really appreciated the security of using Firefox to connect to the internet.

Bresler, You're not the only one. Though with me it's not a preference I have to be on 10.4, it's just what my work computer is on. I have no control over that.

I used this link today: http://www.mozilla.org/en-US/firefox/all-older.html

There's some people who still care about us, users of old OSx.... they have developped a fork of firefox.

http://www.floodgap.com/software/tenfourfox/

Now I'm going soon to move on Windows. So tired of OSX...