Why doesn AIM launch (or an older version of AIM launches instead of the latest version that I have installed) when I click on an AIM chat link in a Web page?
After installing the latest AIM client, rebuild your desktop by holding down the Command (key with Apple symbol) and Option keys while the computer is restarting. That should update your system so that in the future your browser launches your latest installed AIM software. You also need to make sure that “Cookies” are enabled in your browser.