Have you figured this out? I have an issue that is similar, that may be related. When using an external display, my laptop screen is no longer usable since upgrading to 3.2.x from 3.1.x. I've tried using xrandr to turn it on with no luck, the mouse will go off the screen as if it is moved over to that display but the display will not come on. This problem happened right after the upgrade to 3.2.x for me.
