FWIW, we use Deki / AKA MindTouch Core on the TurnKey development wiki. I created an account on it that has Admin privileges and there doesn't seem to be anything I can't do with that account. In other words, if this doesn't work you could try to give special privileges to your new admin account (or any other account). It might require manipulating the database though.
Last time I had a problem the Deki team on IRC were most helpful. You might want to try that. Tell them I said hello and don't forget to come back and share your experience for the benefit of the community!
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