I have this pesky little problem with my SDE instances (running ArcSDE 9.3 with Oracle 11g). Everytime I load a table or feature class into my geodatabase from a shapefile, an sde export file, or from another file or enterprise geodatabase, all of my varchar2 columns automatically are converted to NVARCHAR2 on the load. I asked Vince Angelo about it and he suggested toggling the UNICODE_STRING DBTUNE parameter in DEFAULTS to FALSE. I didn't have this parameter in my DEFAULTS keyword so I added it an set it to FALSE, restarted SDE, but this did not resolve my issue. Any thoughts?