I recently migrated from jboss-4 to jboss-5

When I run the webservice of my appliation locally to find whether it is running, I get this exception

ERROR [org.jboss.web.tomcat.service.jca.CachedConnectionValve] (http-127.0.0.1-8080-1) Application error: TestService did not complete its transaction

Am not sure how to get rid of this exception. This comes after a succesful run of one webservice request. For next request, am not able to hit the database because of this exception

This is how the Transaction manager is configured in my hibernateCfg.xml

<property name="hibernate.bytecode.use_reflection_optimizer">true</property>
        <property name="hibernate.generate_statistics">true</property>

       <property name="hibernate.connection.datasource">java:SsmsDS</property>


        <property name="hibernate.dialect">org.hibernate.dialect.Oracle9Dialect</property>
        <property name="hibernate.current_session_context_class">thread</property>
        <property name="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider</property> 
        <property name="hibernate.cache.use_second_level_cache">true</property>    
        <property name="hibernate.cache.use_query_cache">true</property>
        <!--  <property name="hibernate.cache.use_second_level_cache">false</property> -->
            <property name="hibernate.cache.use_structured_entries">true</property>

             <!-- JBoss transaction manager lookup (begin) -->
    <property name="hibernate.transaction.manager_lookup_class">org.hibernate.transaction.JBossTransactionManagerLookup</property>
    <!-- JBoss transaction manager lookup (end) -->


                <!-- JTA transaction properties (begin) ===-->
     <property name="hibernate.transaction.factory_class">org.hibernate.transaction.JTATransactionFactory</property>
        <property name="jta.UserTransaction">UserTransaction</property>
      <!-- ==== JTA transaction properties (end) -->

In java-code in each method they start the transaction this way

sessionHib.beginTransaction();

Please help me to get rid of this error !

Thank you !!