Apple Portables: Wait for your computer to fully shut down before closing the display
Summary
If you decide to shut down your Apple portable computer rather than putting it to sleep, be sure you allow it to shut down completely before you close the display.
Products Affected
Portable Computers
You can tell when an Apple portable computer is completely shut down by confirming you have a black screen, no active power light, and no fan or drive noise. If you close the display on a MacBook Pro, MacBook, MacBook Air, PowerBook, or iBook while it is shutting down, the computer may not shut down properly.
As an alternative to shutting down your Apple portable computer, consider simply closing the display, which puts the system to sleep.