Photoshop :: Enable OpenGL Shadows Before Render?

I'm trying to do a 3D tutorial I found on youtube.  Photoshop is not behaving the same way as what I'm seeing however.  I think the problem relates to the OpenGL rendering of the shadows.  See te example pics below. 
 
This is the scene lit with 1 point light but not yet rendered.  The shadows on the point light are turned off.
 
This is the same scene if I turn the shadows on:
 
Finally, this is what I get if I render it:

how to display the shadows correctly on the pre-rendered OpenGL version so I can place my light sources.
 
I'm using a W7 machine with a Core i5, an AMD 6870 card, and 16 gigs of ram.  The video drivers were updated today.
 
Also, if I look at the same file on my work computer (with an Nvidia Quadro M card inside) it works fine - the pre-rendered view (with shadows) looks great.  Is there some Photoshop preference or graphics adapter setting I need to be using?