i purchased a power adapter for my macbook pro < 1 year ago, but i don't have a receipt. it recently stopped working. i'm wondering what i should expect if i take it to an apple store and try to get it replaced? will they have a history of my purchase? i'd just go and figure it out, but we all know how slow and painful the waiting for help can be at the store, so i'd rather not take a trip there just for that if i'm only going to be out of luck. any insight would be great. thanks!