I finally find out why Vue was so stubburnly refusing to use any materials in the Preview windows. The answer is simple because the default setting is set to use grey. At least on my system it was set to default grey.
This option is not in the Options menu window as far as I can see but in the top panel of the tool panel on the right of the screen.
When an object is selected and the Aspect tab (left most tab) is selected in the top panel there is a small pull down menu for selecting the colour you want objects to be in the preview window. This was set to grey. There is an option A which I assume stands for Automatic. When I selected this all objects in the scene suddenly appeared in full colour with the correct materials applied. This setting is remembered for other scenes that may be loaded.
Problem solved.

Now, what amazes me is that E-ON did'n't know about this option. If they had then surely they would have told me to check it. Also, why on earth was the default set to grey and not automatic??

Thanks for all your helpful suggestions guys :)

regards,
Isaac