Why do I get ODBC driver authentication denied when using unixODBC's isql and DataManager?

In unixODBC 1.8.8 and earlier, isql and DataManager pass in a database user name and password to SQLConnect even if you do not specify them. isql takes two optional arguments after the DSN. These are the database user name and database password. If you omit them, isql passes empty strings to the Easysoft ODBC-ODBC Bridge, which believes a user name and password were specified and therefore doesn't pull the TargetUser and TargetAuth out of the DSN.

If your ODBC driver requires a user name and password and you are using isql or DataManager, you must specify them either on the isql command line or in the DataManager dialog box, when prompted.