Camera memory card virus, keeps on reappearing?

I believe the viruses are actually on your computer rather than the memory card. Last year my school was infected with the autorun.inf virus. Their ideas on its origin on our network was that a student had the virus on his home computer, used his flash drive there, and then used it again at school. The virus then moved itself onto hundreds of computers on the network and onto every flash drive used on one of the infected workstations. This was a huge problem, and the entire network was shut down for about three weeks. Luckily, you don't have nearly as many computers to repair. Download or install an AntiVirus program and run a full scan, the infected files should be found and removed. Always make sure you have AntiVirus software installed, because a virus can cause huge problems eventually. Good luck!