I have a 2-month-old 15" unibody MBP and I just noticed a black mark on the keyboard area of the case. It's a hairline black horizontal 0.5" line above the right arrow key. Here's what I don't get. I inspected this thing very thoroughly when I first got it so I'm sure it wasn't there before. On top of that, I've had a Moshi Clearguard on this thing since day 1. In fact, when I first saw the mark, I thought it was just dirt on the Clearguard. I absolutely babied this thing. I have no idea how this could possibly have happened. Even if a bit of dust got under the Clearguard, it's not in an area that gets any significant pressure. I'm still trying to determine if this is a mark or if it's actually a scratch. If it's a scratch, it must be really light because I don't feel anything. I tried rubbing it with my finger and a damp microfiber cloth, but there's no change. Does anyone have any suggestions?