AutoCAD Civil 3D :: Coordinate Transformation Results

I am using Civil 3D and Map 3D 2010.

I have some points in a drawing set up in a coordinate system and using a specified point file format, I successfully exported them to another coordinate system for use by our surveyors. I also wanted the pipe route in my destination drawing so I created a shp file from a polyline representing the pipe route in the original drawing using Map 3D Export. When I imported the shp file into my destination drawing there appears to be a slight horizontal difference from the point locations. The shp file doesn't land directly on the points.

To try another comparison, I ran a query on the pipe route to perform a manual coordinate system transformation. The result of this is the exact same as the shp file.

My questions are, which method (exporting points vs. shp files) results in the correct coordinate transformation and why are they different? When exporting points I am not using any specific transformation settings, I am simply selecting the destination coordinate system. When exporting a shp file, Map 3D creates a prj file from the specified coordinate system in the drawing. Are there any other settings I need to adjust to get the same result with both processes? The only thing I can think of is I only have the coordinates out to 4 decimal places in my point file format, do I need to go out farther?