Virtual Furniture Scene - Changing prefabs for my own - can't get it to work.

Hi All.

I am playing with passthrough and the Virtual Furniture Scene.  I can get it to work fine.  Now I want to replace the standard furniture items with something else (a rock for instance).  This is so that I can build a scene that uses the objects in the real world as scenery (and the user wont bump into them - in theory).

The problem:

* I can add a rock (for instance) as a child to the original prefab (the table) and it appears in my scene but is unscaled.  So I know that there is no problem with the actual prefab (the rock) itself

* When I create a new scaleable prefab (i.e the rock prefab with the added 'Pivot' game object and the 'Simple Resizable' script) - adding it to the Plane and Volume runs the apk happily but my new object (the rock) doesn't appear in the Scene.

I am stumped.  I cannot see any problems.  The Resize script is - simple!  It should just be scaling the object that it is attached to but doesn't seem to want to for some reason(!).

Any ideas??