Qubes R32 screen blanking except active window

[Gaijin]

I'm encountering seemingly random screen blanking while I'm using Qubes
3.2 (updated from a fresh install of rc3). The screen will blank and
momentarily show the logon. Yet if I move the mouse or use the keyboard
only the active window will show. Changing desktops, clicking on other
windows, or moving the active window around will redraw the rest of the
screen.

I never had this issue on this hardware with R3 or R3.1. I'm running
dual monitors off an nVidia GTX 560 Ti. The screensaver is set to blank
the screen and require a login. That's the screen that keeps popping up.
Sometimes it gets so frequent that I need to reboot the system and the
problem will go away for a while.