I was playing around with settings on my D40 tonight trying to learn it (I'm a noob to photography). I was just taking random shots of my ceiling and I noticed a red spot (pixel?) in the same location of every shot. I really hope it's just dust or something, but I wouldn't think it would be red if it were. But then again I am totally new to cameras and photography so I wouldn't know for sure. Anyone ever seen this before?