mine developed one of these today. only about 3mm and is not an even shape, kinda banana shaped. i *thought* it might have been caused when i removed my invisible shield screen protector. it was pretty well fixed and tugged the screen a fair bit to the point where it could see it bowing a little! howver, after reading this thread seems like it may just be coincident. dont really want to have to send it in for a replacement since everything else is perfect. if anyone finds a way to remedy the problem please please post.