Thanks for the reply jh.
My router is powered off at the mains several times a day. As part of my green credentials I try to turn the power off all my kit when not in use.
Nevertheless, I also hit the hardware reset button (to factory default settings) ... no change. I have also tried my PC on one of the other connections (just in case it is a hardware prob with one of them) ... no change.
I can't help thinking that it is a "simple" thing to an expert ... and it is my fervent hope that someone can just say "Oh, you just need to change the such and such setting to ..."
Here's hoping.
Regards
Graham