A solution to MySQL ODBC error ‘connection using old (pre-4.1.1) authentication protocol refused’

If you get this error, the problem is that your user’s password hash that is stored in mysql is old.
You have to update your password like this:

SET PASSWORD FOR 'bob'@'%.example.org' = PASSWORD('cleartext password');

You can set the same password you already had, it will just update your password hash.