Just had accountancy exams (which I passed) hence not been active in this topic for a while.
Ubuntu can duplicate the displays using the Displays control panel (tick button for Mirror Displays,) but apparently the only resolution available is 640 x 800 which doesn't work with my configuration.
EDIT: Tried with Nouveau driver as above, didn't work, so tried porprietory driver again (this time in 64 bit Ubuntu) and got the following error mesage when I started the Nvidia control panel:
You do not appear to be using the NVIDIA X driver. Please edit your X configuration file (just run `nvidia-xconfig` as root), and restart the X server.