Again, Steven. If you power and unpower a servo either by switching off power at the switch or by unplugging it and plugging it back into the receiver the servo will twitch. This is normal. Have you done a range check with the engine running and with it off? Your radio manual should have some recommended min distances for a range check. Something really obscure - Is the transmitter antenna screwed in tight? Could be an intermittant connection in the switch wiring also. It wouldn't hurt to get in there and wiggle everything until you get a response. If all else fails, switches are relatively cheap. Buy a new one.