Did you run the MCPR removal tool after uninstalling the old applications? If not, try it, linked in my signature.
You don't mention what operating system and service pack this is or what browser you are using, but that blank business used to occur in beta versions of Internet Explorer.
If you are running any beta version uninstall it and then install the latest, which is IE8.
If you are already running IE7 or 8 go to Tools/Internet Options/Advanced and click "Reset". OK any prompts then click Apply and OK.
Close and reopen IE and then go to Tools/Manage Add-ons and re-enable the add-ons.