When a light set does that, go ahead and kill P5. Reopen your scene, apply the lightset, then resave it back to your library. Delete all the lights in the scene (best way is to use the delete lights python script in freestuff), the apply your just saved light set. That set will no longer give you any troubles. Best thing to do is save your scene before switching lights so you have something to go back to if that happens again. Foxx