I have a Canon A720 powershot. All was working fine for months. Took the SD card out to download pictures, replaced it in the camera and now I cannot review any pictures on the camera. I toggle the switch to look at the pictures and the camera powers off. When I turn it back on (in the review photos mode) it says there is no memory card. If I put it back into take pictures mode and cycle the power off and on, the error is gone and I am able to take pictures. They register on the memory card, but I am never able to see pictures on the view mode. I take out the card, and download to the computer and all is fine. I am just not able to see any pictures on the camera. I have switched memory cards, changed batteries with no results. Anyone ever seen this before??