Tonight I did an update and then hit "restart." The computer starts, the apple icon and the wheel/clock icon appear, but it does not boot. After a few minutes, the computer turns off by itself. I already went on to the Apple site support pages and nothing was helpful (I tried the reset options, mainly). This is a 2006 MBP that was repaired in 2007 for similar problems. Obviosuly, it's already out of warranty. I need help... please!