I’m developing for android and I just started using lightmaps. In this particular scene the walls just use the cube mesh that comes with Unity. I put the lightmap resolution up all the way to 250, but it still looks like this:
[13133-unity+2013-07-14+15-00-58-60.jpg|13133]
As you can see, rings of light are visible. I suspect it might have something to do with texture settings but I can’t be sure.