Leo says it isn't a problem with the cards, it's an autorun program on the SD card that is running that prevents it. He can remove the programs by formatting them (using a camera is great for that). Leo says to buy cards that are made for photography. They come with no additional autorun software.
If that card has U3 on it, he has to go to the manufacturer's site and get the U3 removal tool. He can get Sandisk's U3 removal tool here. U3 is a security risk, and Leo recommends removing it on anything it may come installed on.