Dell 4320 - Can't get HDMI to work?

I've run into an odd, I think, situation with a Dell 4320 projector and HDMI.   When my laptop is set to duplicate screens, the projector doesn't find the source.   If I pick any other option (extend screen, just projector) it works fine.  

If I use VGA, everything works fine. 

Any ideas why HDMI and duplicate don't work? 

Thanks!

K