How to reproduce:
Select a map where the first player in the list is a computer-only.
Then click on "Random Map".
Then click on "Show Advanced Options":
And then push "OKAY":
Oh, and when i moved "Lord Kilburn" Hero, i had two of him. A copy of him remained in the castle, if i click on him with the Helm-cursor, it select the one i moved (the real one xD). After pushing at the beginning of next turn, the ghost-one disappeared.
________________________
~Lands of Enroth~