In this case, the cable network operator has to switch the satellite receiver in his head end station to the format "letterbox". This makes sure that 4:3 programs are automatically shown as 4:3, and 16:9 programs in the so-called letterbox format (in case of 4:3 view screens this means black bars above and below the picture).
Please be so kind as to give us the name and - if possible - the address of your cable operator so that we can inform him about the switch.