My battery for my 17" PB seems to be going wack or something. It drains even when the PB is asleep, not much but a few %. Also, I get about 2hours of battery life with the screen brightness all the way up, and energy saver set to longest battery life. With the screen brightness turned down to the last dot I get about 3 hours and it used to be 3.5hours.......what can I do? Thanks!