Playstation Move calibration?

Playing Move with Bratus Minor got me thinking about the calibration of the controller and how it just didn't gel with movements on screen.

The basic calibration is to point the controller at the camera and press the Move button, easy enough except the camera can be placed either on top of or below the screen. Now consider I'm 6ft (ish) and Minor is 3ft (ish). If the camera is on top of the screen I'm level with it, but if it's at the bottom Minor's level with it. So what? Well it's less to do with the camera and more to do with it's position relative to the screen. How does it know that when I move the controller upwards I'm pointing at the middle of the screen, but Minor has to point the controller at a greater angle to accomplish the same? The answer seems to be that it doesn't.

This showed up in the "Tumble" demo calibrate in this way, but hit Circle to reset the centre. Both of us had to constantly reset the centre and it still didn't feel right, you'd point the controller directly at a block on screen and it would be too high or too low - there was no method of 'point the controller at the centre of the screen and then at the corner indicated' which would have been a much better calibration method.

Oh and Minor 'broke' the tutorial by accidentally flinging the block he was supposed to place on the base behind the camera. As that part of the demo hadn't been reached the camera controls were locked out so he couldn't pick up the block despite the urgings of the game.