sometimes when my MBP turns off the monitor for power save, when it re-activates, the screen is black. I get the password dialog, but then the screen is black. If I hit the power button, I get the dialog for sleep/restart/cancel, but if cancel, the screen is black. Weirdest of all, if I hit fn-F8 I get the display of all my spaces, but when I choose one, the screen is black. This is obviously a software thing, something is drawing that black box, but if I do the force quit, I quit the active app and not the screen power saver. Each time this happens, I have to power-cycle the machine. Really annoying.