A month ago I decided to take my bottom cover off to clean out any dust that may have accumulated! I live in a university dorm and that ventilation is not that great. Dust builds up! Anyways... Every since, I have began to notice some noises that were not present before the operation... I'm talking about a slight metallic/glassy creak that resonates from the middle of the bottom case. It usually only occurs if I flip my MBP over and press in the bottom cover, but I have began to notice it occur at random times just by pressing on the palm rest areas... Is this something I should be concerned about? I have found a fix for this problem. Remove the grounding bar or place a piece of electrical tape on the bottom case to prevent the pegs from scrapping against the bottom case (which causes the noise) Do these modifications affect AppleCare?