My mbp won't go to sleep when i close the lid, and if I try to open the lid the screen pops up then darkens and I have to used the brightness buttons to allow me to see the screen again. I have reset the PRAM and the SMC, but neither has helped any ideas as to what could be causing this to happen? as far as I know it just started happening suddenly. When I close the lid I hear the fans still going and the white led on the front stays constant. Even the sleep fx under the apple logo doesn't work.....