How common is dust and other unknown marks under the glass screen? Mine has at least 2 spots under the glass that I could only describe as looking like tiny pieces of glitter. They don't rub off and there are no bumps/ridges when I try to feel - I'm positive they are under the glass. I also have a few marks at the top of my iPad under the screen that look like scratches - but again I can't feel them. They've been there from day 1 - can't see them when the iPad is on - and it's not the comet streaks I understand every device is going to have some marks and it's not affecting the use of it. So yea I'm being picky and am curious how common this really is?