Ran into a little problem yesterday. I woke up my PowerBook from sleep and the screen turned gray. Rebooted about 5 times with the same result: I would get a happy Mac and the spinning beach ball and then gray. I ran Disk Utility from the 10.1 CD, with no problems found. I ran the hardware test twice, with no problems found. I ran fsck starting up from single user mode, with no problems found. Out of desperation, I started up holding down Shift, and it booted fine. So my question is, what doesn't load when you hold shift and how do I fix it? I am running 10.1.3 only. Thanks.