id	summary	reporter	owner	description	type	status	component	version	resolution	keywords	cc	guest	host
16370	Main window showing guest freezes after using virtualdesktop on Win7	P-Dog		"Host: Windows 7, running virtual desktop program Dexpot version 1.6.10, Build 2362. 
Host Video card: NVIDIA GeForce GTX 960
VirtualBox version 5.1.12r112440 (QT5.6.2)

Guest OS: KUbuntu 16.04.1

This behavior started after I just upgraded from VirtualBox version 5.0.?? to version 5.1.12. 

When VB is in fullscreen mode, on the host I switch virtual desktops away from the desktop showing VB guest OS. When I switch back to the host virtual desktop the guest OS screen is frozen. HOWEVER, the VB preview window works. I can see applications switch, and can use a console to tell the machine to reboot. 

The screen does not feeze if the VB guest OS is kept in Windowed mode (not full-screen mode). In fact, switching to windowed mode unfreezes the display. 

The attached log is after the guest screen freezes, then I switch VB to windows mode to unfreeze the display, then switch virtual desktops on the host a couple of times. 
"	defect	new	other	VirtualBox 5.1.12				Linux	other