I have reinstalled and everything appeared to be ok apart from the problems mentioned in my last reply.
I then updated and ended up back to square one with no desktop bars or icons. Unfortunately I did not observe which updates were applied, update just said there were 135 to install. I presume at least one of them was graphics related and I presume there is a log somewhere of what was updated.
When I was able to access the additional drivers there was a beta driver from nvidia which I tried activating but nothing useful happened.
Is there any further information I could provide which would assist anyone in finding a workeable solution to this problem.
It is very frustrating because all previous incarnations of ubuntu have worked 'straight out of the box' as it were but 12.04 seems to be a whole different ball game.