JollyRoger:
Apparently Micro$oft decided to quietly add the .NET framework to Fire Fox in a windows security update. They made it an add-on but with no way to uninstall it through the add-on menu. You in fact have to manually delete it from the registry and delete the sub folder it resides in.
Found the article at: http://voices.washingtonpost.com/securityfix/2009/05/microsoft_update_quietly_insta.html
Removal can be found here: http://blogs.msdn.com/brada/archive/2009/02/27/uninstalling-the-clickonce-support-for-firefox.aspx
ZWarrior:
ya know, I was wondering where that came from when I rebooted last update. Thanks for the update.