exception; Another resource already exists with name - pick a diffe

我使用了atomikos来实现JTA事务，之前一直运行好好的，可是最近一直报个问题

[code="java"]
Caused by: javax.naming.NamingException: Another resource already exists with name dataSource_mailbill_slave - pick a different name
at com.atomikos.util.IntraVmObjectFactory.createReference(IntraVmObjectFactory.java:94)
at com.atomikos.jdbc.AbstractDataSourceBean.getReference(AbstractDataSourceBean.java:369)
at com.atomikos.jdbc.AbstractDataSourceBean.init(AbstractDataSourceBean.java:276)
... 70 more
[/code]

我的bean.xml配置如下：
[code="java"]
<!-- atomikos事务管理器 -->

init-method="init" destroy-method="close">

UserTransactionManager



true

 <bean id="atomikosUserTransaction" class="com.atomikos.icatch.jta.UserTransactionImp">  
    <property name="transactionTimeout" value="300" />  
</bean> 

 <!-- spring 事务管理器 -->  
<bean id="springTransactionManager"  
    class="org.springframework.transaction.jta.JtaTransactionManager">  
    <property name="transactionManager">  
        <ref bean="atomikosTransactionManager" />  
    </property>  
    <property name="userTransaction">  
        <ref bean="atomikosUserTransaction" />  
    </property>  
</bean>  

[/code]

请问，是什么原因呢？