Here's a quick modeling, the left imported from SU to blender, (blender produces similar topology after a boolean operation), on the right a different topology without triangles (the good one). This, on the right, doesn't seem to cause these photon problems in render engines. That's why you should expect lighting problems near arcs. See this nice link, kerkythea has some similar problems there.
http://forums.sketchucation.com/viewtopic.php?f=81&t=22695
IMHO
[image: afZR_Picture1.jpg]