I think either you need to experiment with how soft or hard you make the normals or try selecting which edges you want to be soft and which you would want to be hard. I would select all of the edges, soften them and then select the edges around the rim and harden them. If you are still having problems, make sure that all of the normals are facing the right way - try using the Edit normal tool to see which direction the normals are facing - you can also use the append tool as it highlights borders between faces where the normals are facing the opposite directions.

Hope that made sense.