Thanks for you input Sean.
I tried doing what you recommended but no rollback option was available on either driver.
However uninstalling the Nova-TD diver using the delete option removed both drivers, and Vista restarted. Once the stick was connected Vista put them both back on without any option not to.
So I uninstalled the Nova-T driver and the OS kept the TD version. On reboot it asked to install a driver. I cancelled with the option do not ask again for this device, but it continues to do so on every connection.
Device Manager now shows a Nova-TD diver installed and the Nova-T as an Other Device and no driver installed. The TV works in this situation.
We have a clue of what is wrong. With both drivers installed the TD shows under driver details 3 paths to driver files, the T only 1 path.
So hence the confusion. I may have to rollback windows. I do have the update to Windows7 option and the disks if this is a better option.