Comment 13 for bug 294791

I have a similar problem and I know how to trigger it.

The keyboard stops working, but it still accepts ctrl+alt+Fx, so I can switch to VT and restart metacity (or compiz, it happens in both). However, unlike Cory, I can still interact with menus and the GUI in general with the mouse.

What triggers the keyboard freeze in my case, is adjusting the brightness with the function key Fn+up/down arrows.

I've seen one mention that this is caused if you blacklist the 'video' module, but it's not blacklisted in my case.

my kernel and Xorg logs have nothing noteworthy.