Trying to get the PiP option to work on this TV. We are using a One For All URC-6011B00 remote, a digital cable decoder and basic cable. I've read another post where they recomended splitting the cable signal at the wall so we have done that, now I can get the PiP screen to have a different antenna source from the regular screen. Pressing the TV/VCR button changes the antena source to A or B on both screens. How can I change this?