Thats the strange part, it shows on my camera that I'm over exposing if I go higher, I'm not sure why. Unless 0.3+ or 0.7+ doesnt mean clipping? I thought it did though. Even when I expose more, it still has the same amount of noise, but I'll do another test again when I get back home.
Also, make sure you're looking for the noise in a dark room so you can see the shadows better. I notice it a lot on the corner wall and the desk.