My computer sits on my desk most of the time. I unplug it about once a week to cycle the battery, but for the most part it doesn't move all that often. It's just about two years old now and about a month ago I took it to a business meeting and noticed it didn't sit flat anymore. It was slightly off, but i figured it was nothing and put it out of my mind. My office is very dusty so every few months the computer starts to run hot and i take the bottom cover off and blow the dust out. When i took it off, I noticed that the battery (all four of the cells) is puffy. So much so that couldn't even get the clips in the middle of the bottom cover to snap. I noticed once i had the cover back on that it is slightly warped where the battery is putting pressure on it. What i am asking is, has anyone experienced this on a computer that is so relatively new? The battery monitor app I downloaded still shows it as good and it still holds a full charge. I've made an appointment with the Apple Store for Sunday, but i'm almost wondering if i voided the warranty even opening the case at all.