Seeing the 3D room, i htink you have the same problem as some of us.
A8 lightening don't allow to have "glued" 3D models with same light color at snapped vertex frown

I've seen complex 3D tiles glued perfectly on Unity3D and they had light, normal map and no visible seam at all !!

Just do It !!

http://independentcreator.over-blog.com/pages/3D_Models-7792999.html