This is a bit of a basic question but I'm having trouble with it. I want to use a light set I have created in one scene in another scene. I can't find a way to save a light scene (I have Poser 2012).

One thing I have tried which didn't quite work as I expected was to use the "Memorise" lights from the edit menu then opened my new scene and "Restored" them. This kind of workled in that the lights were brought back but their positioning in the new scene was off centre. In the initial scene the lights were focused on the main figure but in the new one they were pointing somewhere else... Both figures are centred according to their absolute positions (all at zero) so I'd have expected the lights to keep the same relationship to the new figure in the new scene.

Any idea what I might be doing wrong? 

You can safe your light set in the library.
There is a "Light" button for that in the top row; The Lightbulp button.

As above, but note that by default the positions of the lights are saved (and loaded) relative to the 'Universe'. You can do things to change that behaviour. 

Thanks guys, that pointed me in the right direction! I knew it had to be something obvious but though I've taken plenty of things out of the libraries before I haven't put much into them. When the set was restored from the library it was positioned correctly (the universe was aligned the same in my two scenes) 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.

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.