I have a late 2013 13" rMBP with OS X 10.9.2 and the past two weeks it has been acting strangely. Often, it doesn't sleep although I close my lid. And it isn't because I put it in a bag or something just after closing it. This morning I woke up and opened it to see that it was at 45 % (closed it at 100 %) and it wasn't as cool as it is when it has slept for a while (it stands close to a window so the aluminum gets quite cold at night). And at first it showed 100 % while coconutBattery showed 45 %. This doesn't happen every time I close the lid, just sometimes. Anyone have any experience or know how to fix this? I don't have any new apps running or something that could have caused this.