Neville, you are wrong. All Airbus load calcs are completed by the flight crew from information spat out from the gate scanners. If something goes wrong with those scanners then it is the old rubbish in rubbish out scenario.
Let's not forget that Tiger were grounded as their safety system wasn't addressing the incidents NOT because of the incidents themselves. As said above the safety culture at Jetstar seems to be quite good since the crews are self reporting these things and the ATSB are getting notified at a very early stage.