Hi JohnF I have powered off the router and re-booted my laptop...receiving the same error message as before, in the same circumstances. Like the previous member, I have also been receiving this message for several months BUT only once at startup.
Just been to my wife's PC and that uses the same account for CBF. Hers was at the logon screen with the user id and password boxes blank BUT still responded to page requests, with no intervening message. Interesting! Having logged off and back on, she now has the same problem as me. Do you want to take this dialogue offline, via email, or what?