Initial Wireless Router connection problem.

I have a Belkin N+ Router (F5D8235-4 v1) which I am trying to connect to VIRGIN broadband via a motorola surfboard cable modem. I have followed the initial cable setup routine. After booting the modem (which is fine after 60 seconds) I boot up the router. After 20 seconds (as recommended) The Power light is solid Blue (working fine), the connection to the PC is also working fine but the modem light flashes amber. When I insert the setup cd and start to proceed through the setup routine, the modem connection test fails. I have tried a full shutdown and reboot in PC - Modem - Router order. Still the same. I tried swapping the rj45 cables around and still the same result. I have shut down all firewalls and still the same. I have tested both rj45 cables as a direct connection between PC and Modem and get an internet connection. Any guidance would be appreciated, thank you.