Spring + hibernate :Initialization of bean failed

[csdnbig]

applicationContext.xml配置如下：
<beans>
<!-- config the session factory of hibernate -->

<bean id="hbSessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="configLocation">
<value>/WEB-INF/classes/hibernate.cfg.xml</value>
</property>
</bean>

<!-- Transation config org.springframework.orm.hibernate.HibernateTransactionManager-->

<bean id="myTransactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory">
<ref local="hbSessionFactory"/>
</property>
</bean>

<!-- hibernate DAO config -->

<bean id="cohabitationDAO" class="com.xlands.ilove.hibernate.dao.CohabitationDAO">
<property name="sessionFactory">
<ref bean="hbSessionFactory" />
</property>
</bean>

<!-- local permanence service org.springframework.transaction.interceptor.TransactionProxyFactoryBean-->

<bean id="xlandsCohabitationService" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
<property name="transactionManager"><ref local="myTransactionManager"/></property>
<property name="target"><ref local="cohabitationTarget"/></property>
<property name="transactionAttributes">
<props>
<prop key="find*">PROPAGATION_REQUIRED</prop>
<prop key="save*">PROPAGATION_REQUIRED</prop>
</props>
</property>
</bean>

<!-- CohabitationTarget primary business object implementation -->
<bean id="cohabitationTarget" class="com.xlands.ilove.bso.implement.XlandsCohabitationServiceImpl">
<property name="cohabitationDAO"><ref local="cohabitationDAO"/></property>
</bean>

</beans>
--------------------------------------------------------------------------
web.xml中：
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/classes/applicationContext.xml</param-value>
</context-param>
----------------------------------------------------------------------------
调用：
context = WebApplicationContextUtils.getRequiredWebApplicationContext(this.getServletContext());
XlandsCohabitationService server = (XlandsCohabitationService)context.getBean("xlandsCohabitationService");
---------------------------------------------------------------------------
错误如下：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'xlandsCohabitationService' defined in ServletContext resource [/WEB-INF/classes/applicationContext.xml]: Initialization of bean failed; nested exception is java.lang.IncompatibleClassChangeError: null
-----------------------------------------------------
我的排除是xlandsCohabitationService段配置事务错误，但是我参考了所有例子，都没有找到头绪。希望高手提醒一下小弟。thanks

[csdnbig]

补充一下：如果没有配xlandsCohabitationService的bean，那我这样拿别的bean是可以拿到的。我是在servlet里调试。