Comment 18 for bug 267188

I also upgraded from 8.04 and after that I also had issues with the nvidia driver until this week when I finally found out what helped.

When looking in the package manager I found that even though I had selected to use the nvidia 177 driver, the package was not installed.

When I manually installed the package, it also installed the source package and the kernel-headers-rt (real time kernel)!!!!! which off course was not correct. Trying to uninstall the kernel-headers-rt said it had to uninstall the nvidia 177 driver too which I did not want.
In the end I installed the correct kernel source package (kernel-headers-generic) and this triggered dkms to rebuild the nvidia driver.
After a reboot finally the startup (without the splash) showed it succeeded in loading the nvidia kernel driver and from there on I was able to set it up using the 'Hardware Drivers'.

One last thing I needed to do do enable dual monitor setup was to run

sudo nvidia-config
and
sudo nvidia-settings

Hope this helps