I got my 15" Powerbook second hand a couple of months ago and been working away happily on 10.5.8 since then. From this morning however if I close the lid of my laptop without shutting down my computer goes into a deep slumber from which it cannot be awoken. To get it to restart I need to unplug from the mains and remove the battery. The only sign of life is the glowing light next to the button to open the lid. Anyone have any ideas as this is really starting to annoy me!?