I have one of the newer 2.16 MBP's, and I have charged the battery twice. The first full charge said I had about 2:00 of battery, and now its saying 3:10 on the second full charge. Is it going to keep going up? my roommates older MBP keeps a charge around 3:30-4:00. Anyone have any insight? could it be the 7200rpm hard drive?