The card in a PC or card reader. Try another card. Try removing the card, and the batteries, count to 10, put batteries in, card then power up.
Bob
I have 256 mb sd card in digital camera-minolta dimage F300. I formated the card by mistake and now my camera does not recognise the card at all. Is there any thing i can do ?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic