So earlier this week my '09 15" Macbook Pro's track pad stopped clicking. I figured "well maybe I need adjust the pressure" so I took out the battery and it clicked fine. Put the battery back in, but then the door wouldn't close. After several minutes of scratching my head, I looked at the battery's silhouette. It was swollen. A little bit, but enough not to be able to shut the door. So off to the apple store I go. (I have applecare until 2012 BTW) Well the 'Genius' that helps me is familiar with the problem, and says "well I have to run a diagnostic on your machine so they'll let me give you a battery..." I'm like sure whatever. She plugs in an ethernet cable into the port and spends about 3-5 minutes running diagnostics. When she turned it on she held down like, the H key or something, then pressed like caps lock a few times. After she ran that she's like OK let me go get you a new battery. What I'm curious about is what the "Diagnostic" test was for, and what information does it look for? In b4 "you don't want them to find your porn".