Right this is doing my head in and I'd really like to know how many of you have this backlight issue: On a dark/ black background how many of you with iMacs experience backlight leak which makes the screen in parts lighter than the rest of the dark background/ screen. Like a silvery tinge if you like. With mine it's at the bottom right and left part of the screen. It's my 4 th machine and this is the only issue I have with it, no yellow tint just this. How many of you have this?