You should not have to uninstall 11 to update to 11.0.01. You would have to uninstall the product from your target machines if you wanted to update to 11.0.02. That is, you can't update patched installs; you can only update over the base version. That 'gotcha' is why most admins use the boostrapper deployment method.
What I was asking was if there have ever been a 9.x or 10.x Acrobat or Reader on that machine (or any version in a different language). If that is the case, I'll send you off in another direction. You'll probably need to uninstall the product and/or clean those machines with http://labs.adobe.com/downloads/acrobatcleaner.html.
Did you look at the solutions in the related posts?
http://forums.adobe.com/message/4415286#4415286
http://forums.adobe.com/message/4329735#4329735
etc.