Bug: Change in spelling of GCS_Deutshe_Hauptdreiecksnetz (DHDN) caused inability to perform data transformations on older data using the Projection Engine.
** This issue is addressed in ArcSDE 9.0 Service Pack 2 (SP2) **
The name of the DHDN coordinate system was taken from EPSG (European Petroleum Survey Group). Originally, this was spelled as GCS_Deutsche_Hauptdreiecksnetz. At a later release, EPSG fixed the spelling to GCS_Deutsches_Hauptdreiecksnetz. German clients have problems with this spelling change, because when attempting to do a datum transformation on data with the old coordsys name, the transformation searches for the new name, not the old, so no match is found.
Click on the link in Related Information below to download the Service Pack, if necessary. **