Without knowing what you are trying to do, it is hard to say.
Check the machining preferences, within the Rhinocam Browser. "Part sampling resolution" can be adjusted there.
Also, check the tools_options menu. If you select the "Units" tab, try setting the absolute tolerance to a reasonable value of, say, 0.001".
Another interesting thing about rhinocam, is that it converts your Nurbs surfaces to mesh, before creating 3D toolpaths. For larger, more complicated files, sometimes I convert them to mesh myself, and hide the nurbs surfaces during the tool-pathing.
Hope this helps. Don't be afraid to call MecSoft. They are very knowledgeable and helpful.