Move your mouse over the objects in the wrl to affect the other frame.
|The red cone writes html directly into the frame.|
|The green sphere loads an html file into the frame.|
|The blue cube loads an html page containing just a wrl into the frame.|
|The purple cylinder loads a wrl file directly into the frame.|
In some web browser and vrml plugin combinations the purple cylinder and red cone cause problems. In those cases I think it might be that in order to write to a frame there needs to be a pre-existing html page there. If there is no html there then it silently fails.