We bought a Polaroid i830 for our teachers to use. I have only used the camera a few times. I let another teacher use it, and now it says "Card Locked". It will not ler me take a photo, download pictures, anything. Have any suggestions?

Take the sd card out of the camera.

Look along the edge, somewhere there is a small tab on it, it moves back and forth... on one side there is a picture of a closed padlock, on the other end an open padlock.

Move the little tab towards the picture of the open padlock, then put the sd card back in the camera.