When my screen is closed the computer continues to run, and does not respond when the monitor is reawakened. Furthermore, upon shutdown, I have to remove the battery and reset power management in order to get the computer to turn on. If I just shut it down, the computer refuses to come on, hearing the hard drive make its sound before just going out to lunch. Disk Utility says the hard drive is okay because it would not get past the black screen. Each time when the computer is restarted it starts up like the operating system was in hibernation.