Hey folks, I'm using a relatively new macbook pro here, and I'm only getting maybe 3-4 hours of battery life... closer to 3. isn't this thing supposed to get more like 6 or 7? i've got wifi off, bluetooth off, screen dimmed, and the inferior graphics card running. just chatting on AIM and browsing the web right now... nothing too intense. what do you think is going on? thanks!