My nikon 5700 is about 2 months old. Everything has worked perfectly fine until now. When I plug it in to transfer to photos to the computer, the computer doesnt read the card. I know the computer see's that the camera is plugged in because the little icon for when you want to unplug it comes up. When the camera is not conected to the computer, I am able to view the pictures just fine on the computer and take new ones. I have 2 CF cards, and the computer is not reading either of them. What do I do?