Hi all,
I think I understood how it works...
In the Wii version, you can't mix Toyboxes. You also should save them on differents saves.
For exemple, you should use one save for Building ToyBox, another one for Sports Toybox etc...
If you load a predefined toybox and build on it, every other toybox is deleted !
Imagine you build on "sport toybox", you save... that's ok, when you'll load the game again, your changes will appear.
Now, you want to build in the "race toyboy" and then you save... if you use the same save slot, your changes will appear on "race toybox" but the "sport toyboy" is initialized and you lose every changes made on it !
Wii version really seam to be a "light version" of the game...