Just a thought, but check with the other guy and see if he changed the crystal in his Tx to a different channel without getting it re-tuned. Same goes for your Tx. Was the crystal in your Rx changed? Futaba has low band and high band Rx's. Changing the Rx crystal to a channel in the wrong band can open the door for interference from another Tx on a different channel. Just a few possibilities. Something is definitely askew if another channel is causing your servos to go nuts.