>Do you know if my guess is close about why you can't refer to the parent of an object made via CREATE vs ADDOBJECT?

Yup, right on: There is no implicit relationship between a reference and its referrant like you have between an object and its container. If you need such an association, you must have a back-pointer (if you want a peer-to-peer relationship), or a reference to an intervening mediator (for an indirect linkage).

My base classes have a LogicalParent property which I use for such back ponters, among other things.