Bug or not about ASCII and Multi-Byte character set

version: psqlodbc 08.00.0101 and 08.00.0102

The server database encoding is ASCII in win2000. After inserting several multi-byte characters with pgAdmin3(version: 1.2.1), i found the odbc driver can't provide the right data (application is written in visual c++ and call ODBC API to access db server). All displayed multi-byte char set data were not correct but the ASCII data was right. However, pgAdmin3 can correctly insert and select all data .

Then i read the "mylog" file and found the multi-byte data have been got correctly from server.
Is it possible that some function (maybe the converting function) have a little bug?

P.S.
if the server db encoding is UNICODE and producing a new psqlodbc.dll through deleting all SQL*W function in 'psqlodbc_win32.def' file, i got Delphi applications using odbc driver can show all right data.