I let my Macbook Air 11" sleep for like 4 hours yesterday. The battery was full when I left it but was at only 35% when I opened it. Even if it didn't sleep properly which could have happened, it wouldn't drop by 65% in 4 hours. It lasts longer than that when I use it normally. Isn't this thing supposed to have really long stand by time or whatever they call it? Anyone else have this problem?