Description of problem:
The right half of the desktop is black when connecting via VNC client to a
system that has dual spanning displays (with dual video cards).

Version-Release number of selected component (if applicable):
vino-2.8.1-1

How reproducible:
Every time with given configuration.

Steps to Reproduce:
1. Configure dual monitors with two video cards (in my case nv Quadro 540, NVS
50 PCI) and spanning display (xinerama on, clone off, quadro 540 uses nv driver,
NVS 50 pci uses vesa). 
2. Enable Remote Desktop.
3. Connect via VNC client.
  
Actual results:
Half the VNC display is black. The mouse tracks incorrectly depending on the
monitor arrangement (leftof/rightof).

Expected results:
VNC client should show both displays and the mouse should track seamlessly
between them.