i have the tivo hooked thru a motorola cable box using a serial cable. since i've received the refurbished tivo the channel changing is acting weird. when i punch in the number to change to another channel and hit enter, the screen starts to turn over to new channel, but the blue screen which says that channel is not received flashes on for about 1 sec,[it's probably less, but seems like a second, more like a blink of an eye]. I have restarted the tivo several times and redid the channel lineup several times. and yes the serial cable is plugged in the whole way on both ends.
ps, this didn't happen til i go the latest tivo.