Hi,
Since the VB 5 betas, I experience that my guests screen sometimes goes black when I logout from Windows and sometimes when the screen saver comes in or when resuming a saved state. The VM will then no longer react on any command. Even ACPI shutdown doesn't work. I never saw this with 4.3.* on the same image. I suspect this bug to be introduced in beta 3, but I'm not sure.
Unfortunately, I cannot 100% reproduce the issue.
Machine: Dell Precision M4800 (NVIDIA graphics, QHD display)
Host: Linux; Fedora 21 64-bit with NVIDIA binary driver (346.72)
Guest: Windows 7 with non-WDDM driver from matching guest additions installed.
I tested with another Windows 7 install with WDDM driver installed. It seems to be fine on BETA4 (the only one I tested).
Any clues?
Cheers,
Bas.