I had the same exact problem. It turned out to be the USB cord. Is it a standard one that you can get anywhere or one made specifically for the camera brand?

Also, if its warrantied, you can send it bck t the manufacturer and they'll fix it real fast - mine was back tome within 4 days!

If you can't get the USB cord or send it back to the maunfacturer, you can buy a card reader - I think they are fairly cheap.