I have a ZClass (Shot) which is nested beneath a container ZClass (Storyboard). I.e., an instance of Storyboard might be: Scene1 (Storyboard) - shot1 (Shot) - shot2 (Shot) - shot3 (Shot) ... For reasons that I cannot discern, copying and pasting instances of Shot does not work. I can copy them, but pasting creates a broken object: "This object is broken because the unknown product that created it is no longer installed or is installed incorrectly." I suspect the copy has in fact worked because the title in brackets is that of the source object. This is an isolated problem on my site. All other nested Zclasses work fine but I cannot pin down the difference. This is Zope 2.1.4. Has anyone else encountered this problem? Darran.