Hi, I have experience solving Nvidia graphics problems in Ubuntu.
For better guidance, I think you should go to the thread in my signature (not the bootinfoscript link).
In that thread, there is a user named RawGod whose instructions are good enough to follow.
Summary of steps is to
1. Start afresh (not meaning to reinstall, just disable nouveau and do not use Nvidia drivers provided by Ubuntu, the proprietary ones in hardware drivers.)
2. Then go to Nvidia's website and get the driver for your Nvidia card. (get the linux version)
3. Turn off gdm by executing
Code:
sudo /etc/init.d/gdm stop
4. Install drivers by executing
Code:
sudo bash <your Nvidia Driver's directory>
5. Start gdm again.
Code:
sudo /etc/init.d/gdm start
Good Luck