I've recently moved into a new house which has twin sat cables in the lounge. I'm trying to get Freesat through the Manhattan SX box which only has one input. I've plugged one of the cables in but during installation/tuning I get the "Main Freesat Transponder Not Found" error. I've checked the LNB on the dish and it's a Sky EL021 which I understand should be compatible. Any ideas on what the problem might be? Many thanks!