Ok, after entering search terms in many different ways all I kept finding were people with the same problem and no one with a fix for it. I kept trying because I think it is ridiculous to have to create a new user account just to narrow down the conflict. I finally found a thread on the Adobe support forums that linked to a fix that worked for me. The reason that I had the problem on both of my computers, but only with my user account, is due to MobileMe syncing my settings. I tried the fix on my iMac and didn't have to do it on my MacBook because MobileMe took care of it for me. I have always expected more from Adobe than this, but the conflict seems to have nothing to do with Adobe Air runtime and the fix is just as stupid. Adobe really needs to get on it and patch this problem. Here is the link to the guy who posted the fix that worked for him and me on his blog. You'll see why I am amazed at how stupid and unrelated this problem, with it's accompanying cause and fix, are so outrageously stupid. I hope it works for the rest of you, also.
http://andrewapeterson.com/2008/08/os-x-adobe-air-installation-problem-solved/