[vtkusers] screen will not refresh!

[Janet Kim]

Hi,

My problem is that whenever I load some new data
(interactively from a menu), my render window goes black.
Then when I use the mouse to click inside the window,
the scene shows up, updated polydata and all.

I've tried calling vtkRenderWindow's Render function,
but no luck.  It's been a problem for a while that I've
been conveniently ignoring, but I really have to address it
now.

Does anyone know what could possibly solve this problem!?
I'm using tcl/tk.

thanks
Janet