Try adding your router IP to the DNS and Gateway settings. Think your router IP is not the usual 192.168.1.1...
I added a Roamio and did not add in the DNS and Gateway IP to my wireless. I did with the Series 3.
Series 2 (PLS, sold)
TiVo HD 1TB (157 HD Hrs, PLS, "652")
Roamio! Oh, wait, Its Juliet!
OTA! OTA! OTA!
The TiVo Apocalypse begins on Sat 2013 Feb 16 00:00 GMT!