I know I used to have shadows in Preview Mode,  but since I've had 11 on this machine(about 2 years now) my shadows are gone in Preview Mode.  I've been working by doing a render in preview for the Cartoon/Comic Book,  then  a render in Firefly for shadows(shadows only setting),  and then  compositing in PS...

...well I'm sick of doing that, I just  want my shadows back in preview mode, what  gives?

I've tried every setting I can think of,  OpenGL is enabled everywhere, settings for hardware shadows are ticked on in preview, shadows are enabled on the lights(raytrace shadows,  tried every bias setting between 0-and-40)...

...nothing I do will produce shadows in Preview Mode. 

I know this used to work--I know it did--so  what gives???

Any help pin-pointing the root cause of this would be greatly appreciated.