I've recently baught an 8 GB SanDisk sd card and it worked in both my friend's Nikon and my school's Canon cameras, but when I tried it at my Canon camera, the card wasn't working. It said my SD card was locked though the switch says otherwise. I've tried multiple cards and they were said to be locked. My camera used to work just a few days ago. Could my new SD card be the problem?
Read more: Can and sd card break a Camera's sd card slot?