when I install a 603ff rx into any of my nitro 1/8 scale rigs the servos twitch and jump around real bad, but if I put that same RX into an electric powered car it works fine! what is the deal with this? I only have one of the 603ff rx all the rest of mine are 603fs. I dont think it is a noise or heat problem because the nitro car dosnt have to be running for this to happen. I am also using a 3PKS tx. this has me puzzled