Almost everyday now, most often if my fans are running, when I close my computer screen, my macbook will wait about 15 seconds, and then turn itself back on from sleep. I know it does this because I see the Apple on the screen illuminate, and the disk drive makes noise. After waking for about 3 seconds or so, it simply goes back to sleep, and repeats itself. It has been driving me CRAZY! Because of this, my battery is dying much quicker. I don't know how to prevent this problem from happening! Please help! Thanks in advance.