I am working on a large number of similar animations.  I just noticed that the animations which have the lights moving were all saved on the last frame (it's a project where clips have to match up together, so I am rendering beginning or end frames for comparison).  The clips that were saved on the first frame don't have the moving lights.  I could turn lights animating off, but now I'd have to do it for every clip, and it's quicker to just re-load correct lights.  I should definitely have done that when creating the initial scene though.