[vtkusers] Problem with vtkPolyDataMapper

[Pascal Augustin]

> It should work as you expect. Something else is going on. Can you post a small, compilable example that illustrates the problem?
> 
> Bill

Hi, 

 I've tried building a simple python test app, but I can't seem to reproduce the bug. It's particularly annoying since it happens so easily in my original application.  I'll try building another test app and investigate this a bit more later this week. In the meantime, I'll take David's advice and avoid sharing mappers between actors. 

Thanks

Pascal