Easysoft ODBC-ODBC Bridge was changed in version 1.0.0.27 to require the LogonUser and LogonAuth attributes (see the Changes.txt file entry for 4-Apr-2001). This change was made because a number of new ODBC-ODBC Bridge users were getting confused by the authorisation error 87 (invalid parameter) when LogonUser was not specified and authentication was enabled in the ODBC-ODBC Bridge Server.
Prior to 1.0.0.27, if you had authentication turned off in the ODBC-ODBC Bridge Server, you did not have to specify LogonUser/LogonAuth. From 1.0.0.27, if you have ODBC-ODBC Bridge Server authentication turned off, you will have to specify a value for LogonUser/LogonAuth, although the actual value is meaningless.