Hello, I have a HP Probook 4540s laptop running Windows 7 64-bit. Just recently I noticed that at nigh my laptop will for some reason turn itself on and then off with a blank screen, I saw that happen a couple of times when I had a bad sleep during night. Just wondering if there is a way to fix that and if that is something to worry about? P.S. The laptop is not really off. It's either in sleep or in hibernate mode. Thank you.