I was cleaning my screen with glass cleaner (lens cleaner, more specifically) and the cloth that came with the MacBook, and I noticed 6 perfectly equally-spaced circles -- either water marks or something on the screen. When dry, they are not visible at all. Could this be a slight manufacturing defect? Or maybe just an artifact of the construction process? I use a Moshi ClearGuard on the keyboard, but these are not the shape of the keys, and any finger oils wiped off perfectly with the lens cleaner. Since my screen is usually dry, I don't really care about this unless it can cause problems later on. Do any of you see this on your MacBooks?