why does my camera preview screen show on selecting 'Preview'

Unable to recognise files.......why?

It's a card used last week with no problems. 2GB SD card. Fortunately was taking same pics with my canon powershot 480 which frankly performs better.
Thanks

Bob, August 2014

Ok lads and lassies have reformatted and it works.
It was a card formatted to my canon I accidently picked up. Cards for Agfa are now colour coded.

bob, August 2014