But in my environment in WinXP professional with sp2 client, there is the same problem as win2k.
I used postgresql 8.0.3 win32 installer to create the db server.
Multibyte characters are written correctly but readed wrong by the ODBC driver. Seems to work on WinXP clients right. Only Win2k clients may have this problem. This bug may be corrected in PostgreSQL 8.1.