suburban, That optical kill switch has brought the radio frequency noise that could be on the ignition line from the ignition battery in close proximity to your RC system. There is no isolation there. You may be coupling right in to your receiver. Remove your kill switch and all its wires and connect your ignition battery straight to the module. This one gives you the isolation you need. The other one does not.Dan.
http://www.smart-fly.com/Products/Ignition/ignition.htm