Originally Posted by Tinkster
Try to run
and follow that with (if it doesn't produce any errors):
X -config ~/xorg.conf.new
If you get an error message from that, try posting that here.
Nvidia cards require the Nvidia driver (proprietary or otherwise) to install. It's relatively simple, but I don't know if any Live Cds have native nVidia support? (And I think ATI has issues as well) You can download the driver from the nVidia website and it is very easy to install. Now Ubuntu is based off of Debian so there may be a nvidia-kernel-image somewhere in the packages for Ubuntu (not sure), that would be the easy fix, but if you do that don't use the propietary driver.
I've got Dual Montior on nVidia geForce5500 so I know you can do it!
EDIT: There are tons of HOWTOs out ther for nVidia Drivers, Since you're using Ubuntu, I would search for nVidia Ubuntu, or nVidia Debian and see what comes up. As I use LFS now (despite my screenname) my setup was a little different, and from what I remember from Debian there is a distro specific way to setup nVidia.