Xorg randomly refusing to update screen and ends up blank after restarting it
At random intervals (and I do mean random), X will stop refreshing the screen---for all practical purposes and by all definitions, it's frozen solid. Whatever it was trying to display at the instant Xorg decides to sulk ends there. Switching to a virtual terminal works, but switching back to X ends up with either a black screen, or the frozen state. Quitting Xorg altogether brings me back to my login prompt (agetty or Qingy) just fine, but logging back in and starting a new X session just produces a black screen.