Quote - so it is just the "memorise" and "restore" functions that didn't do what I was expecting and seem wrong... I can live with that now.

'Memorize' will not carry over to a new scene. When you open a new scene, Poser loads the 'preferredState.pz3', and the lights you get are whatever lights are in your preferred state, and the their memorized values will be what ever their memorized values were when you set the preferred state.