I have the new aluminum macbook, and it's been fine up till the 10.5.6 update. Now every time it sleeps it won't wake up. The screen doesn't turn on, I hear the fan whirring, but it never actually turns back on. I have to hold the power button down, shut it down and restart it. This really sucks, it's a huge inconvenience. I called Apple and they had me re-install OSX and it was fine, but when I did software update again it started all over again. I upgraded to 4 gigs ram a bit ago, but didn't have a problem till now. Can anyone help?