Today I hit the power button on my Mac Book Pro, got the light blue boot screen with the Apple logo and the spinning load wheel, and it never moves on from this screen. What can I try, and does this mean that my hard drive is toast? I updated to Leopard at the end of last month, and added CS4 about two weeks ago. Other than that, it was working fine before I powered down the day before. Thanks in advance for your help.