Can anyone help me out here?

I'm trying to get my DSL-G604T (D-Link wireless router) to authenticate users via RADIUS.

I have MS IAS running on Windows Server 2003, the server and router are setup fine (as far as I can tell) but my Vista laptop fails to connect every time. I have googled and googled as well as tried around with whatever I can think of and can't get this to work.

Does anyone know of a detailed step by step guide or how to do this? Thanks :)