How can I fix my remote Central locking? [2006 Hyundai Getz 1.4)?

My remote central locking has suddenly defaulted. I can lock manually and then press the button to activate and it works perfectly to unlock. Also, it used to lock automatically when starting the car but now you hear a click but it doesn't lock - again I have to lock manually. When I stop the car it unlocks perfectly again. Could it just be a loose connection somewhere?