Baldrick, thank you..!!
I only hit a wall when I wanted to click Save, particularly as a large, orange-backgrounded Changes Must Be Saved appeared in the Home/Advanced Settings/Broadband banner. Eventually, I read on and just left it, which worked.
A BT engineer arrived this morning, in response to ultra-slow broadband speeds with the previous PlusNet router, and helped me out too, so now I think I've achieved flying speed :).
