I am a newbie to the forum and will appreciate any help. I have the Nikon D90 and have recently experienced a very odd problem. When I turn on the camera and do nothing else immediately after wards, the shutter freezes. The shutter can be pressed but with no reaction from the camera. I do not get an "Err" message on the top LCD. Also none of the buttons on the camera work. I have to turn off the camera and turn it back on in order for the camera to function properly. However if I turn on the camera and immediately (w/in a second or 2) begin to press the shutter or use any of the buttons on the body the camera will function as usual. Also the camera sometimes freezes if at some point I stop pressing any of the buttons or shutter. Do I have a defective camera? I welcome any comments or advice you may have and thanks in advance for your help.