Cycles Normal Bake does'nt bake indents that are not tapered I can bake high poly normal maps with a lot of success, however if I try to bake a very simple indentation on a cube with no tapering I get a flat baked normal map, please see the below image to clarify what I mean.


I dont know I am doing wrong because if I scale down the indented face slightly it will bake the normal map correctly, as seen in the image below.
You're not doing anything wrong, what you want to do is just not possible to achieve with normal maps. If you look at it from the top, you can't see the sidewalls, therefore no normal information can be baked to the normalmap (the normal-information for the sides is infinitely small). normal maps can't represent height differences – only differences in the orientation of the faces.