in re: using glowing boxes as light sources in a no-lights scene, they may not work like the various other light types:

• they may seem to directly illuminate a diffuse/specular posersurface, but they may not do GIbounces off diffuse surfaces (e.g. girl in white room, walls with normals forward)
• they may not interact with atmosphere
• et al.

I dunno when they'll add real area lites to poser.