I've always had a problem with my D90 overexposing. I would say 95 percent of my images are taken with -3/6 being "baked in" using the b4 fine tune optimal exposure menu setting. This gives me a zero (balanced) meter reading with -3/6 baked in. Maybe its just my camera, or some of these d90s, but even with this -1/2 I still usually have to dial in additional underexposure if there is any sunlit areas in a mixed lighting scene. I would say the majority of images i discard are due to blown out highlights that are unrecoverable (CNX2 and RAW). I continually struggle with overexposure even with this -1/2 stop baked in. Evenly lit scenes with lessor dynamic range of illumination are ok, when i get into medium to high contrast settings with sunlight/shade I usually will need to dial in additional minus exposure compensation. I have shot identical images with another semi-high end camera (non Nikon) that i have and do not have this problem with that camera.