Can Anything Be Done about the Overlapping Light Issue?

[Joelaff]

If I have two lights in the same place that are identical except that one is set to not affect spec and refl, and the other is set not to affect diffuse I find one often has trouble rendering. Both lights are set to invisible and not set to occlude other lights. Sure would be nice if you didn't have to offset lights every time you do this sort of thing.

[hermit.crab]

No issues here. What kind of result are you getting? Otherwise, you could use LPEs instead of cloning lights as discussed in this thread.