Yesterday I was having router troubles with Asus DSL-N55U and swapping an exact copy router with the exact same config SSID and keys but my Pansonic TV wifi wouldn't accept the swap and insited I go through the setup process and re-enter the same key.
Is the TV filtering the router by MAC because that is the only thing I can think of. Other wifi gadgets Phone, desktop PC with wifi happily reconnected to the spare router?