Ok. This thing WILL NOT work. It scrolls up, it scrolls left, it scrolls right, but it will NOT scroll down. The only way it will go down is if I press really hard on it. It is really annoying me. I have only had this since July when I got my mac. I have tried everything. Upside down cloth. Alcohol swabs. Rolling on paper. Please help! This is annoying me so much. Is it covered under Apple's Warranty if I bought the Protection Plan for my MacBook at the same time?