I am getting an error when I try to set up a many-many relationship and need some expert advice

Hibernate version:
2.1.8
Mapping documents:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >

<hibernate-mapping package="org.tiaa.scmtool.model">
<class
name="CmfTlUsers"
table="CMF_TL_USERS"
>

<id
name="usercode"
column="USERCODE"
type="int">
<generator class="native"/>
</id>
<property
name="userid"
column="USERID"
type="string"
not-null="false"
length="31"
/>

<set name="roles" lazy="false" table="CFM_TL_GROUPUSER">
<key column="usercode"/>
<many-to-many class="CmfTlGroups" column="groupcode"/>
</set>
</class>
</hibernate-mapping>
Code between sessionFactory.openSession() and session.close():

Full stack trace of any exception that occurs:
04:51:03,115 ERROR JDBCExceptionReporter: ORA-00933: SQL command not properly ended

04:51:03,147 ERROR JDBCExceptionReporter: ORA-00933: SQL command not properly ended

net.sf.hibernate.exception.GenericJDBCException: could not initialize collection: [org.tiaa.scmtool.model.CmfTlUsers.roles#2002112]
at net.sf.hibernate.exception.ErrorCodeConverter.handledNonSpecificException(ErrorCodeConverter.java:90)
at net.sf.hibernate.exception.ErrorCodeConverter.convert(ErrorCodeConverter.java:79)
at net.sf.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:29)
at net.sf.hibernate.collection.AbstractCollectionPersister.convert(AbstractCollectionPersister.java:728)
at net.sf.hibernate.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:291)
at net.sf.hibernate.impl.SessionImpl.initializeCollection(SessionImpl.java:3315)
at net.sf.hibernate.collection.PersistentCollection.forceInitialization(PersistentCollection.java:336)
at net.sf.hibernate.impl.SessionImpl.initializeNonLazyCollections(SessionImpl.java:3168)
at net.sf.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:143)
at net.sf.hibernate.loader.Loader.doList(Loader.java:1063)
at net.sf.hibernate.loader.Loader.list(Loader.java:1054)
at net.sf.hibernate.loader.CriteriaLoader.list(CriteriaLoader.java:118)
at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:3660)
at net.sf.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:238)
at org.tiaa.scmtool.model.base._BaseRootDAO.findAll(_BaseRootDAO.java:340)
at org.tiaa.scmtool.model.base._BaseRootDAO.findAll(_BaseRootDAO.java:315)
at org.tiaa.scmtool.model.base._BaseRootDAO.findAll(_BaseRootDAO.java:302)
at org.tiaa.scmtool.ShowUsers.main(ShowUsers.java:38)
Caused by: java.sql.SQLException: ORA-00933: SQL command not properly ended

at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:134)
at oracle.jdbc.ttc7.TTIoer.processError(TTIoer.java:289)
at oracle.jdbc.ttc7.Oall7.receive(Oall7.java:582)
at oracle.jdbc.ttc7.TTC7Protocol.doOall7(TTC7Protocol.java:1986)
at oracle.jdbc.ttc7.TTC7Protocol.parseExecuteDescribe(TTC7Protocol.java:880)
at oracle.jdbc.driver.OracleStatement.doExecuteQuery(OracleStatement.java:2516)
at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:2850)
at oracle.jdbc.driver.OraclePreparedStatement.executeUpdate(OraclePreparedStatement.java:609)
at oracle.jdbc.driver.OraclePreparedStatement.executeQuery(OraclePreparedStatement.java:537)
at net.sf.hibernate.impl.BatcherImpl.getResultSet(BatcherImpl.java:89)
at net.sf.hibernate.loader.Loader.getResultSet(Loader.java:880)
at net.sf.hibernate.loader.Loader.doQuery(Loader.java:273)
at net.sf.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:138)
at net.sf.hibernate.loader.Loader.loadCollection(Loader.java:1020)
at net.sf.hibernate.loader.Loader.loadCollection(Loader.java:995)
at net.sf.hibernate.loader.CollectionLoader.initialize(CollectionLoader.java:83)
at net.sf.hibernate.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:288)
... 13 more
Exception in thread "main"
Name and version of the database you are using:
ORACLE 9i
The generated SQL (show_sql=true):
select roles0_.usercode as usercode__, roles0_.groupcode as groupcode__, cmftlgroup1_.GROUPCODE as GROUPCODE0_, cmftlgroup1_.GROUPNAME as GROUPNAME0_ from CFM_TL_GROUPUSER roles0_ inner join CMF_TL_GROUPS cmftlgroup1_ on roles0_.groupcode=cmftlgroup1_.GROUPCODE where roles0_.usercode=?
Debug level Hibernate log excerpt: