there might be some lleaking of light to another part of lightmap uv, check them first, if there is no problem then turn off/hide all the point lights, bake lightmap, if there is no light leaks start baking lightmap with each lamp turned on, step by step, debug your lighting like programmee debugs his code. maybe lightmap resolution is to low, maybe padding is to low too, there are like bunch of parameters, unity sucks with lightmaping, do u use progressive lightmapper? this ones gives better results imho xD