Use All Displays In Full Screen will only clone, not extend

I upgraded to the July Tech Preview when prompted last week.  Prior to the update, I had dual screen working in two different Windows 7 VMs.  Since the update, setting View, Use All Displays In Full Screen will only clone, not extend the screen.

This happened when I initially installed the Tech Preview as well.  In that case I was able to toggle the setting back and forth and it started working.

When I look at display customization under windows it only shows one monitor and it doesn't find another when I click "Detect".  I am able to use the displays independently in MacOSX.

This is on Mountain Lion, MacPro, Late Model 2009, 22GB memory.

What to do?

Thanks,

Dale