I'm running a fresh Karmic install. Installed the proprietary driver through Ubuntu, then later installed the latest Nvidia driver using the Nvidia installer. I have an 8400GS graphics card, hooked up via DVI to a Sony HS420 TV. Overscan is severe and I can't read my subtitles.
Others have told me that nvidia-settings is supposed to have a slider for overscan compensation, but mine does not. I have run apt-get install --reinstall nvidia-settings, but the slider is still not there.