Problem with LinkSys WRT54GS & Eircom Netopia Cayman 3341

I am trying to install a LinkSys WRT54GS wireless router for a friend, but not getting anywhere.

They have Eircom broadband with a "Netopia Cayman 3341"

The LinkSys has a setup wizard, which asks for the DSL username and password, and we used the standard userid and password "eircom" and "broadband1". but it cannot connect to the internet.

We also used "eircom@eircom.net" as a user id, with the "broadband1" password but nothing works.

Do i need to change anything on the netopia first, before this will work.

As per the Linksys manual, the netopia is connect to the "internet" RJ45 commetion and the computer connects to one of the other lan ports.

Is there anythnig else i need to check ????

thanks