PreparedStatement.setNull()的bug??

The follow statement execute error using 9i driver(Oracle JDBC Driver version - 9.0.2.0.0).
throw UncategorizedSQLException(Invalid Column Type Exception), 
errorcode: 17004.
Upgrade to Oracle JDBC Driver version - 10.2.0.1.0, it is OK.

Example:

......
PreparedStatement pst = cn.prepareStatement("select sysdate from dual where 1=?");
pst.setNull(index,  java.sql.Types.NULL);   -------- throw exception!!
......