My daughter just came up with a solution. She took out the card and breathed into the slot (like you would an old nintendo game.) It worked!!! Very coolThanks!Tim
I also have a rebel T3i and have the same problem. I have tried changing cards, newer or older it doesn't recognize that there is a card in the camera. I checked each card on my computer to see if the camera was misreading the card and was saving pic...