It sounds like a similar problem. I think the following sorted my problem out.
There used to be a file called /etc/X11/xorg.conf that was used in Ubuntu to hold information about the x windows. This is no longer needed, however Nvidia driver still needs this file.
Firstly make sure you have installed the Nvidia package.
(ctrl + alt _+ f1)
sudo Xorg -configure
sudo nvidia -xconfig
The plan being this should create the missing file xorg.conf. Then the nvidia driver can write to it.
You can then check the nvidia settings in System>Administration>Nvidia X server settings> and System>administration>hardwaredrivers
However this often a difficult problem, as you can see from the number of other thread on the issue, and there is a chance doing the above might break it.