Striped photos

I just bought this camera, an upgrade from the dmc-lz2 which i thought was fab but whenever i take a photo on it the picture is covered in horizontal lines, it shows both on the camera display screen and on the actual photo when i put it onto the laptop. it even hapens with the factory settings! the screen is clear when i look at it but as soon as the pic is taken it's covered in lines.
I when I take a photo, the image turns out striped, even though the viewing screen is clear until I take the photo. I tried putting them on my computer, and they are striped there, too. This is not a new camera; it has worked splendidly for many months, and suddenly it can only produce striped photos. Any advice?