>In my understanding, that is exactly the point...When you addobject you are adding an object to the form. Not assigning an object to an existing form property. I don't know how these structures are implemented but it seems to me that they would be handled differently.
>
>>I was using FORM.AddObject and FORM.RemoveObject. I think The CreateObject() approach requires THISFORM.oRef=.NULL.,

They are different, an example of this is that you can assign a different class to the property. AddObject() puts the class in a container that knows how to cleanup its contents on destroy.