And the solution was....
Hello 'pooter people,
the above prob all fixed now. I upgraded the firmware on the router, via the Netgear UK site and after a nervous minute or two to see whether it had taken, was able to re-establish the connections.
The result, was that uplift speeds are now in the range of 70-170KBS which makes life a bit more tenable than 0.3KBS.
I post this cure in the hope that somebody else out there might make use of it in the future.
thanks to all anyway,
Conan