My powerbook will not wake up from sleeping. I have unplugged the battery and the powercord, and it is still blinking....how beats me. I held the power button down for over a minute, 4 sec. should have killed it. The sleep light has been blinking for almost half an hour.... ...wait, it just stopped while I was writing this thread. Is this normal? It would be a neat way to change batteries, but I have never had it do that before. Wierd.