Hi, Rob
I tried what you said first - I reset all of the factory defaults and followed, exactly, what you said above, but it did not work at all - still no connection to the internet. I tried swapping the cables as you suggested, and also tried a couple of different LAN ports on the back of the router, in case the one I was using was faulty, but no change.
As for the modem, it is an ntl:250 modem
this one here, and yes, I can connect fine with the modem connected directly to the PC, with no router in between.
Aagorn, if you think that it will help posting the screens then I will give it a go