I just recieved a d40x and noticed something similar, i get one small green dot. I believe these are just burn out pixels, so you should have anything to worry about. I dont even really notice anymore, just when there a black screen.
The monitor may contain a few pixels that are always lit or theat do not light. This is common to all TFT LCD monitors and does not indicate a malfunction
Its not gonna affect performance or lead to any future problems, its just a minor annoyance.
So dont go blaming your crap pictures on your messed up pixels, haha
