I just thought I should rephrase this. What I meant was that I have a theory that Ran never really stopped suspecting Conan of being Shinichi.
Also I just finished watching Metropotalitarian Police Love Story 4, and there was a scene that made me think that Dr. Ariade knows that Conan is behind the Sleeping Kogoro.
never mind, I found out that the Dr. Ariade in that episode was appearantly Vermouth in disguise (unless I'm mistaken).