Thanks for your suggestions and comments. The drive is recognised as the correct machine - it is a Lite-on EHBU212 external blu-ray writer ... here is a snap of how it is shown:
It is USB 3.0 attached to a laptop which has an internal DVD writer, as you can see.
I note that the Windows 7 driver is the one from Windows itself, which a generic windows cd-rom driver. There is no updated driver with the drive and no driver available from the Lite-on website. As I noted before, the drive operates fine using creator writing data files to blu-ray disks, it's just the writing of video that is an issue.
Do you think the windows driver could be fooling the creator software to think there is no blu-ray drive available so doesn't install the plug-in?
The new project menu appears as above, but without the blu-ray options which is consistent with the unavailability of the drive icon.