That was my initial thought re Tewkesbury, hence my contact with Swindon who were more than happy to help. They ordered a second card and, as mentioned, liaised with yer man at Bristol. But no result! Tewkesbury have ordered several cards (allegedly) and liaised regularly with Bristol with the result as seen.
Swindon mentioned that my system appeared reluctant to take the update.
It all appears to point to an issue with my OS. So would loading new PCM s/w solve this or would it be a deeper issue?