Those white horizontal lines appear because of a bug or some kind of an an errror in the browser software - usually Netscape. It has nothing to do with the image itself. In fact, you can hit the "Previous" button and then the "Next" button to return to the page and more often than not, the lines will be gone.
You can also hit the "Reload" button to reload the screen. Reloading often eliminates these irritating white lines as well.