Is there a camera store around that has this printer out as a demo? If so, maybe you can take a memory card there and see if they will let you make a test print or two of the same picture(s) you are having trouble with.
If they come out ok it could be a bad printer. If so, this would give you a strong case for an exchange or refund. Assuming it is still covered.
Also can you take some pictures with a different camera and print those to see what happens? It would be better if you can use several different cameras (borrowed from friends). Take pictures of the same subject under same conditions and settings. If they all come out grainy it is a good chance it is not the camera. If your camera comes out grainy and the others don't then it is a good chance it is the result of your camera.
If they come out ok it could be a bad printer. If so, this would give you a strong case for an exchange or refund. Assuming it is still covered.
Also can you take some pictures with a different camera and print those to see what happens? It would be better if you can use several different cameras (borrowed from friends). Take pictures of the same subject under same conditions and settings. If they all come out grainy it is a good chance it is not the camera. If your camera comes out grainy and the others don't then it is a good chance it is the result of your camera.
