notebook-monitor mirroring not working on Fedora 22

[Robert Moskowitz]

I am not seeing what version of Xfce is packaged with F22 (I just built 
this system; old system runs F21).

Lots of things I have to figure out to get Xfce working as I want it.  I 
forgot many of the customizations I did 6 months ago.  But formost,

When I plug in my external monitor, I can only select laptop, monitor, 
or 'expand to right'.  Mirroring is greyed out.

For some reason, my Belkin KVM is only probing as 1024x768.  I have set 
the laptop resolution at the same, but still mirroring is greyed out.

I really need to get mirroring working before I have to connect this 
system to a projector for a meeting...