I have a macbook. I was using Disk Utility when I saw some disk head errors when doing a "verify disk." I boot into the mac live cd, fix it, and reboot. Upon reboot, I noticed it would freeze on a gray screen. After trial-and-error, I noticed that if I disconnect my USB keyboard, it would boot up fine. I connect the USB keyboard after it is booted, and it does not work. Reboot with it connected, and I get a gray screen. Any ideas?