Code "2503" given on srp5107wm Remote in manual doesn't go through for my Scientific Atlanta Cable Box (Explorer 3250). why not? I follow the instructions. Hold "CBL" button for 5 seconds, type in code "2503" then "power" button for ever and nothing happends. I even waited 15min or until red LED light goes out and nothing happends. I've even typed "9999" and waited. Nothing seems to work. Please help...