I know this reply is too late. But i believe this may help someone in the future. The same thing happened to me yesterday. I was in the middle of a short film shoot and my camera started giving me "Card write protected" message. I searched in the forums and found that it's the problem with the card reader inside the camera. I was left out with no other options at that time, so i tried cleaning the camera's memory card compartment by wrapping cloth at the tip of a small knife. And when i turned on the camera, it got worked like magic. :) Give it a try before spending some bucks on servicing it. Hope this helps.
