I've been having this problem with my Macbook Pro for quite some time now, and it's absolutely infuriating. So far, I've found no solution. As it is out of warranty, I am loathe to take it to the Apple store, but I am beginning to fear I will have no choice. I've got an early 2008 15" MBP with the NVIDIA 8600M GT 512. It spends most of its time in use as a desktop machine, with a keyboard, mouse, and monitor connected, so I don't notice the problem often. However, any time I take my Mac mobile, I am plagued by this issue. What happens is that, seemingly at random, the keyboard and trackpad will completely stop functioning. The only way to get around the problem is to connect a mouse and reboot, which returns things to normal for a few minutes, then it happens again. If I have no mouse, I have to force-shutdown, as the power key still works. Sometimes the keyboard and trackpad will shut down all at once, and sometimes they will fluctuate for a while, with keystrokes not registering and trackpad motions not happening. Sometimes keys will stick (not physically) sending a character repeating across the screen until I hit another key. But, in the end, the result is the same: no input functionality, necessitating a reboot. Sometimes I am able to use my MBP for long periods without a problem. Sometimes it happens within minutes. It happens when it's hot, it happens when it's not. There seems to be no real consistency. For a long time I thought that it was a software issue as it never happened while booted into windows. But recently it has happened while booted into Windows 7, though it never happened in XP. The motherboard has been replaced recently, and the issue did not go away. So it has to be something else. I'm completely stumped.