What you probably should've done after uninstalling the game, was to go and manually delete any files left behind that the uninstaller might have missed. The fact that you reinstalled the game and still found older mods indicates that some files, not originally installed with the base version of the game, were still left behind in the root folder. Sometimes, uninstallers remove all the files but leave the root folder intact if there are still files there that aren't originally associated with the stock version.
