So after using my MPB Retina today, all of a sudden I noticed erratic movements as well as non-responsiveness with my trackpad. To my recollection, no liquids in the slightest have touched the trackpad nor the keyboard for that matter. Any idea of why this might be happening? I do have coverage for the laptop, but unfortauntely this is an older model (Nvidia 650M 1gb dedicated), and they no longer sell these. And from my experience, they usually do not repair older models.