I tried to wake my wife's MacBook from sleep and the screen was black. I couldn't get it to wake up, so I held the power button for five seconds. Now when the machine boots up, the spinning beach ball of death won't go away and the menu bar doesn't fully appear. If I open a program, however, I can use the machine (I'm typing on it now). I've started in safe mode with the same results. I've run fsck and disk utility and both say that the machine is ok. Does anyone know how to fix this strange problem?