something is up with my battery (or possibly something else). everytime ive been running it in class lately, it shuts off at about 40-50%, with no warning at all. i dont know if its a battery thinking it is out of charge (Which would be weird because i just recalibrated it last week), or a heat issue or what. I know the battery isnt really running out, because i can turn it back on a bit later, its at 40%. any ideas? I've had the computer for a year, and I've only run into the problem this semester. Also, minor problem, but sometimes my light on my Magsafe power adaptor randomly goes out. Any ides for that, too?