Sometimes I'm trying to type something and I realize that nothing's getting typed when I press the keys. I don't know what causes this and when exactly it happens, but so far I have not been able to make it go away unless I reboot. When the keyboard stops working, it's completely dead: Not only can I not type, but key combinations like [ Cmd + W ] and [ Alt + Arrow keys ] for swapping Desktops doesn't work either. As I remember though, the light on Caps Lock still works normally. Within one week it has happened to me twice so far, and I rebooted each time and that fixed it.