You experience glitches and artifacts in guest in Coherence or Full Screen view mode with two monitors, "Use All display if Full Screen" option and Aero enabled.
You probably have Nvidia 9400 graphic card which might have issues with Windows Aero and Direct X 10.
Please disable Windows Aero and Direct X 10 following the steps below:
- Go to Virtual Machine menu ►Configure ►Options
- In Coherence section Disable Windows Aero
- Go to Hardware section
- In Video switch from Direct X 10 to Direct X 9.