Thanks Mike for your reply. I think I've dicovered the solution.
The UK distributor here in the UK believes that the problem is a duff 'dongle' as they had received a batch of faulty ones. Here's hoping.......
On another note I understood that VWA 9.0 is only one CD as it is no longer an 'add-on'. The single CD is labelled 'Vectorworks Architect' and appears to feature, when loaded, the 'Architect' elements!
regards,
John K