I had an issue with my Revit MEP 2013 product. When I want to export my Revit Plans to DWG file. My section lines disappear. I attached two jpg file. First one is Revit Plan view, whic is include a pipe and section, also "Hide at scales coarse than" is true. I can see in plan. Second one is DWG file I can only see my pipe can not see my section line and head. What am I doing wrong?