7.1 version and JDBC: how to?

Environment: Informix SE 7.1 on AIX, JDBC 2.2 connection. When I try to execute a simple select, the server returns this error: "java.sql.SQLException: Server does not support GLS variables DB_LOCALE, CLIENT_LOCALE or GL_DATE." I found this note on http://www-3.ibm.com/software/data/informix/pubs/library/notes/relnotes/JDBCdr20.htm "o DB_LOCALE, CLIENT_LOCALE, and GL_DATE are supported only if the server supports the Informix GLS feature. If these environment variables are set and your application connects to a non-GLS server (server versions earlier than 7.2), a connection exception occurs.". I deduced Informix 7.1 doesn't support GLS features... On a newsgroup, I found (maybe) a workaround: "Try unsetting CLIENT_LOCALE and DB_LOCALE and test the connection again." But HOW can I do that? Is it right? Ideas? Thanks a lot in advance. Marco Fabbri