What specific error message are you getting? What type of SD (brand, capacity and speed) have you tried to use? Are you using an SD card or an MMC (MultiMedia Card)? Did you format the card in the camera before you tried to use it? If you did not format the card in the camera then try that first and see if the card works. It is important to do this in the camera and not on a computer as the camera will create the necessary file system on the card for it to work.
