I just purchased this unit from ********** (5 business day delivery) two weeks ago. Like everybody else, I get the "Registration Failure", however, I cannot connect to my cable modem (not router - just in case the router would give any problems) via the ethernet port (Wi-fi works fine). This happen on the initial firmware (148X) on the unit as well as the firmware upgrades (1561 and 1568 - also tried 16XX). What I can do is take apart the unit and check for any shorts, disconnections, etc. on the port, however, there might be something easier to use. Does anyone have any suggestions? Thanks for the help.