I had an unfortunate, but very tiny Pisco spill on my left shift key. Ever since, using the Air keyboard is very difficult. For now I am managing only with a cheap external keyboard. Since Pisco is 40 percent alcohol based, it has mostly evaporated ever since, but the problem persists. Is there a way to clean under the keys without voiding the warranty? I will go to an Apple Store once back from my travels and hope for the best, but for now would like to try to fix the problem myself. It was really a few drops of liquid, but it did its ugly job!!