I have an Asus VK221D 22" monitor. I don't recall seeing these horizontal wavy lines when I first setup this monitor a few months ago, but it may have been there. Anyways I see these horizontal wavy lines from the left to the right of the screen. It's not very noticeable unless you have a solid color background.
I have checked the cables they seem to work just fine, I have tested it with other cables and it doesn't change. I've heard of power electrical issues being the culprit, but does anyone know how I can test this theory?
What about video card settings I have a Nvidia 9800 GT.
Many thanks to all who respond!