I have a different issue with the speaker grilles. I returned my first M8 because the metal(?) plate on the bottom was raised on the right side where it meets the screen, instead of being flush like it's supposed to be. The new unit I got is perfect at the bottom, but now the upper grille is very slightly raised where it meets the screen on the right side (to the right of the camera). I can push it down, but it comes back up after a few minutes (like there's some kind of adhesive that doesn't hold it down properly)... Minor, but very irritating!
Anyone else have problems with the speaker cover plates not being flush with the screen?