I first found the instructions for how to install Nvidia driver in the book "Ubuntu hacks", now I found this http://www.cs.cornell.edu/w8/~djm/ubuntu/feisty/#nvidia-driver or the Ubuntu wiki, https://help.ubuntu.com/community/BinaryDriverHowto/Nvidia

1. Backup your /etc/X11/xorg.conf

    sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf_backup
   
   
2. Install and enable the nVidia driver:

    sudo apt-get install nvidia-glx-new
    sudo nvidia-glx-config enable 
   

   The nvidia-glx-config above are used if you are running "an earlier version" (I guess that means earlier version of nvidia-glx). Otherwise type:

    sudo nvidia-xconfig --no-composite
   
   

   The --no-composite was a fix for some bug...
3. Exit from your GNOME session
4. Press Ctrl-Alt-Backspace at the login prompt to force a restart of the X Server.

This gives an error "Couldn't open module wfb"

Going back to the original xorg.conf, I followed http://www.uluga.ubuntuforums.org/showthread.php?t=514161

@DeleiBio If your card is a Geforce 5200 then you don't need the wfb module which is required only by Geforce 8xxx cards. Any other card would just show a warning about the lack of the said module.

From https://launchpad.net/ubuntu/+source/linux-restricted-modules-2.6.20/+bug/98641/comments/24

I have solved the problem and built nvidia-glx with pbuilder.

Can anyone try it and tell me if it solves the problem, please?

here are the instructions:

1) download this file by typing: wget http://albertomilone.com/ubuntu/nvidia/nvidia-glx-new_1.0.9755+2.6.20.5-15.20_i386.deb

2) type: sudo apt-get --purge remove nvidia-glx-new

3) install the package you downloaded (only for Feisty 32 bit, sorry)

    sudo dpkg -i nvidia-glx-new_1.0.9755+2.6.20.5-15.20_i386.deb 

4) log out and press CTRL+ALT+Backspace

Now I get a Failed to load the NVIDIA kernel module

To permanently fix the driver issue, you need to reinstall the restricted drivers with this:

  apt-get update
  apt-get install --reinstall linux-restricted-modules-2.6.20-16-generic 

now you can boot into the new kernel normally :)

Fuzzy image in S-VIDEO and Composite

Just tested to add the "PAL-B" option to the xorg.conf

    Section "Screen"
    Identifier     "Screen0"
    Device         "Videocard0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "TwinView" "1"
    Option         "TVStandard" "PAL-B"
    Option         "metamodes" "TV: nvidia-auto-select +1680+0, DFP: nvidia-auto-select +0+0"
    SubSection     "Display"
        Depth       24
        Modes      "1600x1200" "1280x1024" "1024x768" "800x600" "640x480"
    EndSubSection
EndSection

I should probably check out Envy next time the glx-driver fails. The drawback of Envy seems to be that I have to remember to manually remove it before doing normal Ubuntu upgrades. http://albertomilone.com/nvidia_scripts1.html