RE: DX6i Binding issues
After you unplug the battery from the receiver, make sure to power off the DX6i. Then turn the TX back on again before plugging in the receiver battery.
If the TX is bound to the RX and remains powered on when you unplug/plug the RX battery, then when you power on the RX again, you'll get the quick blinking light in the RX signaling a brown out recovery.