I thought I'd better let you all know that the router is faulty. Who'd have guessed, brand new out of the box.
I finally gave in and called the help line, (do I hear groans?) we went though the ritual humiliation of establishing everything was working and after 45 minutes the guy finally declared the product faulty.
It's a relief in a way, as I was beginning to doubt my self.
Anyway thanks again for the input from everyone.