During my attempts to "Test Channels" or to "Connect to TiVo", I encounter different errors codes: N01, N04, & N24. I have done numerous things to fix it. I have replaced the cable card. I have rebooted my network's modem, router, and switch several times. I have changed network cables. Even though the TiVo is hard-wired to the router, I have put its MAC address into the MAC filtering list to include it; and I have tried turning off the MAC filtering altogether. I have changed the cable's connection from one position on the 5-port switch to another on the same switch. I have moved the cable from the switch to the router itself. I have restarted the TiVo several times. I check my router and it says that the TiVo has an active DHCP lease on it. The TiVo3's network jack activity LEDs show activity. I attempt to ping the IP address listed on the DHCP lease (192.168.2.86). I receive the result: Reply from 192.168.2.171: Destination host unreachable. (192.168.2.171 is my computer's NIC.) I also have a TiVo1 with which I have no problem. I have used its network cable (with and without the USB adapter) to test the TiVo3. The TiVo1 continues to work without a hitch while nothing I have done with the TiVo3 has made any difference. At no time has the TiVo3 worked on my network. It apparently worked without a problem on its previous owner's network.