Streaking Monitor.

Whenever anything dark is on the screen, it creates dark streaks running horizontally from the dark color. I know it's the video card because it is a new monitor. It's an old HP Pavillion 8670C, and it has a nVidia TNT2 Graphics card in it. I tried updating the drivers, and the setup from the nVidia website said that the graphics card did not match any of the products. So i downloaded the video driver update for the HP Pavillion 8670C on the HP website, ran it, and it still streaks. Any ideas? I'm running Windows XP Pro by the way.