I actually face a similar problem in the game we are developing. We have ~20,000 sprites that have to be destroyed and recreated on leaving/entering the main layout, however, when I make them all global objects (to retain their existence in between layouts) the original placement code somehow mucks up their position on returning to the layout.
I have yet to build a mockup showing the problem yet, but I am going to track this thread to see if any clever solutions to fluidly switching layouts comes up.