I purchased my 17" MacBook Pro last April and noticed a few months ago when cleaning the screen that there were about four small opaque spots in various sizes on the screen. I have always taken great care and never used anything other than a microfiber cloth moistened with a very small amount of water to clean the screen, so I am sure these aren't water spots, although that's what they look like. You only see them when the screen is dark and my MBP is in sleep mode, they aren't visible when it's up and running, so I'm not too majorly concerned, but it does bother me enough to question it. Too, they seem to have increased in number with time. Has anyone else experienced this? And does anyone know what this is from? Thanks for any and all help!