I am posting this from over at the old site, for a user who needed the info pertaining to Civil 3D 2009.
Attempting to export a Shape File results in a CTD. This error has been advertised, and the fix is available, as follows:
Copy the file from the following path:
(XP) -> C:\Documents and Settings\All Users\Application Data\Autodesk\AutoCAD Civil 3D 2009\R17.2\MapExport.ini
(VISTA) ->C:\ProgramData\Autodesk\AutoCAD Civil 3D 2009\R17.2\MapExport.ini
and paste it to:
(xp) -> C:\Documents and Settings\All Users\Application Data\AutodeskC3D 2009
(VISTA) -> C:\ProgramData\Autodesk\C3D 2009
If the command has been run, then a file will already exist. OVERWRITE IT.
This should be fixed in Civil 3D 2010 and 2011.