My MacBook Pro, when charged for an extended period of time with the screen down, goes into hibernation, and has to restart when I open the screen or unplug the power source (you can hear the restart sound when unplugging it). Is this a new feature in Mavericks, or is there something wrong with my computer? I have a MacBook Pro, purchased mid 2012, 8GB RAM which I installed around the time Mavericks came out (I don't think there is a problem with the RAM though). Edit: I have noticed that when my external hard drive is plugged in, this does not occur. Thanks!