Has anyone else experienced "LCD mura" with their Primes, and if so, has the issue gotten any worse since you noticed it? LCD mura looks similar to light bleed, but not in corners of the screen. Rather, it is a small blotch/"bright spot" appearing anywhere on the screen. I have one such problem area that showed up after owning the Prime for about a month. It hasn't gotten any worse, but it's annoying on white backgrounds. I'm wondering how common of a problem this is. A Google search shows that it's a somewhat regular occurrence on cheaper LCD screens.