I recall that when I set up my Series 2 TiVo, the initial setup had to be done with a land line. Only then could you set it to connect via Ethernet (wireless in my case). This was some time ago, maybe they have fixed it. Try
www.tivocommunity.com for info. I'd read about people without land lines having to take the TiVo to a friend's for the initial setup, which takes some time.