Thank you very much, LR - much appreciated but, unfortunately, in vain. I have totally deleted Flash from the 'pooter and done a complete reboot. logged back in and clicked on this thread and instant bloody advert video. The really odd thing is that it only happens on this one thread ! Nothing else in the forum provokes it , nor do any other forums.
I shall leave this thread severely alone and check if the Adobe deletion has enabled other videos. I'll have to open another thread to update.