I have just received my new MacBook Pro 15" i5, however when it approaches the point where it is running low on battery I get the warning to plug it into a power source. Usually on my old MacBook 13" it would go to sleep before actually exhausting the battery completely. So when my new MBP runs out of battery it just powers off completely and I have to boot it again when I plug it into a power source. Have I missed out on some crucial calibration? I did charge the battery fully and then run it down completely.