Problem solved. I don't know what happened to the Plugin Folder during the installation process, but it is no where to be found. I finally downloaded a copy of the previous version, use Universal Extractor to extract the files and copied the plugin folder from that version into the Program folder of 4.0
I'm still baffled as to what happened and why there was no plugin folder where it is supposed to be, even though when you view the add-ons from within the browser, they all appear with an option to disable each. :s (they're hiding some where, where, I have no clue)