Sony dsc-p73 image problems

both my son and myself have the same camera and are experiencing the same problem, after 3 years of excellent performance some of the images are slightly faded and have horizontal lines throughout the whole image as if only some of the information has been processed. the batteries are in good condition and all the pictures were taken whilst on the auto setting. the video capture still works ok but the number of porr images is on the increase. i have a different memory stick but problem remains