I've had my aluminum MacBook for about maybe a month or so now. I've noticed, that no matter how I try, I cannot have it go into sleep mode properly (when I commute/carry it around). Usually when I need to take it to school, I would click "Sleep", the screen would black out, and I put down the monitor. However, when I put it into my backpack - no matter how lightly - it'll start up again! Once, I didn't notice that it started up again, when I brought it out in class, it had dropped from 100% to about 70% as if I'd already been using it. Any suggestions? Thanks in advance.