Hello, I noticed that the +/- (plus / minus) icon keeps blinking on my Nikon D300. I don't remember when and why it started but for a long time, no matter what I do (I played with settings, changed ISO, mods, etc. ) it keeps blinking at all times. Besides that everything seems to be normal, but I am sure this blinking is caused by some kind of an error. Do you guys have any idea what's wrong with my camera? Thank you!