plone.app.theming 1.1.1: editing overlays immediately activated after "copy and activate" or "edit"

[tobiasherp]

I'm sorry, I'm on Plone 4.3, and thus bound to use plone.app.theming 1.1. I'd like to try Diazo-based theming, since it might help me in my task to provide a quite different view to my portal when using a special hostname.
This is what I did:

1. I installed plone.app.theming using the QuickInstaller,
2. visited the @@theming-controlpanel,
3. made a copy of the the example theme,
4. and tried to edit it.

Without any other actions, there appeared an overlay with two buttons (Save and Cancel), and no further text; the Cancel button does nothing visible when clicked first, but apparently tries to submit a form.
The Create Rule overlay (German version here) is activated as well, and it's Cancel button (Abbrechen) doesn't do anything (OK, I can uncheck the use , and cancel after proceeding).

In the logs, I found:

      ...
      File "/opt/zope/eggs/plone.app.iterate-2.1.12-py2.7.egg/plone/app/iterate/browser/control.py", line 43, in get_original
        refs = context.getRefs(WorkingCopyRelation.relationship)
    AttributeError: getRefs

OK, my custom Archetypes-based types are currently not Referencable, but I didn't expect this to be a problem at this point.

Is it just my (heavily customized) setup, or is there a bug in the (quite old) version 1.1.1?
Does plone.app.theming rely on (all?) objects to be Referencable?
Is it just a problem of the controlpanel pages, or am I likely to fail miserably with a filesystem theme as well? (Being new to Diazo and not very experience with XPath, I have hoped to be able to use the assistent.)