There are contents in your post that, perhaps, need clearing up.
1] What was the full message of the "unknown handler" error?
2] What file was it asking for the location to?
3] Do you really have 700 trillion and 1 shortcuts to email addresses? If so, where are these shortcuts? If they are on your desktop, that may be contributing to your problem.
4] What do you mean by "shortcuts to email addresses"? How does that work?
5] Before what was too late?
6] Did this "unknown handler" error occur when you changed your password on AIM, every 6 minutes 23 seconds, (does this include when you are asleep?), before you installed IE7 and/or Firefox 2?
7] What happens if you uninstall IE7 and return to IE6?
Does the AIM web site have any information on this, eg Help & Support, or user forums?
In my experience, Top Secret Spies generally prefer not to broadcast that they are, er.... Top Secret Spies. Possibly I have this wrong?
Is it just me because in the morning I downloaded IE 7 and Firefox 2, and when I went on AOL instant messenger in the afternoon it loaded fine but a message popped up and said "unknown handler" and it wanted me to specify a location on my hard drive. I'm not the smartest out there but I got the feeling that it was probably IE 7 because it's got bugs written all over it. This also happens at random times when i'm clicking on things like shortcuts to my 700000000001 email addresses. I wish I could be more specific on when they occurred but I was to busy sending out an email before its too late(i'm a top secret spy). This also happens when I click on change password on aim, of course because I change my password every 6:23 minutes so its safe. Please help me out, I have windows XP (sp2 obviously)gateway with Pentium d, its official title is a gateway 835GM (sp2 obviously)and a very annoying problem. Oh ya, sorry for the spelling/grammatical errors.