I just noticed my trackpad in my mid 2009 13" mbp wasn't clicking like it should. The buttons still function, but there is no positive clicking on the right side and the left side is stiff and the trackpad is bulging out over the casing. After a lot of investigating, I realized the battery is bulging out some on the right side and if I take the bottom cover off the trackpad works better. I've googled this and can't find anyone with my model who has had this problem. I'm going to take it to get looked at tomorrow. I'm not really expecting a free battery considering the computer is 2 years old now and I replaced the HDD myself, but is there any hope for that? How much do the batteries go for? I really don't want the damn thing blowing up or screwing the trackpad up anymore than it has.