I agree with Greg, use the Tiger One. Pull the RX-18 from the pershing and put it in the T1. If the problem persists, there ya go, it's in the RX-18, but if not, pull the receiver (the green circuit board that connects to the RX-18 via a three conductor wire) and also put that in the Tiger. It seems like you could have one of three problems - either the RX-18 is sending the wrong signal to the units, the Receiver is sending the wrong signals to the RX-18, or the transmitter is sending the wrong signals to the receiver. If you figure out where the problem is you'll know what to replace.