The "ghost" bug pops up in other situations as well. I just made a purchase in the store (while signed in), and the "Sign In" screen appears, with the "Buy" greyed out. I enter my password, and the episode starts to download, but the "Sign In" screen goes into its "infinite loop" thing until I hit cancel.
Another (unrelated?) thing that has started to happen is that I have started getting double downloads of TV shows.
For instance, after the action described above, Itunes also began downloading another copy of Defiance, Episode 09, which I had previously downloaded on Tuesday, and is still in my library.