Digital camera not recognizing certain downloaded pictures?

Hello, I just got a new Kodak Easy Share C143 camera. I had a bunch of downloaded pictures from the internet (google and facebook) on my old card. You could see all those pictures on the back screen on the camera on my old camera. But when I put that card in this new camera, only a few of the pictures show up on the screen of the camera. Only about 1/4 of them show up and the rest of them say Unreadable format. All of the pictures on the card are in the JPG format so I don't see what the problem is. What can i do to fix this? what is wrong? thanks