spring添加事务管理后出错，求救！
所用框架是struts2_spring2_hibernate3，在没有为spring添加事务回滚前没错误，可是添加后就报了这个错，这是为什么？
2008-4-3 15:52:30 org.apache.catalina.core.StandardContext listenerStart
严重: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'BaseDao' defined in ServletContext resource [/WEB-INF/classes/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError
Caused by: java.lang.NoClassDefFoundError
at org.springframework.aop.framework.Cglib2AopProxy.createEnhancer(Cglib2AopProxy.java:224)
at org.springframework.aop.framework.Cglib2AopProxy.getProxy(Cglib2AopProxy.java:151)
at org.springframework.aop.framework.ProxyFactory.getProxy(ProxyFactory.java:110)
at org.springframework.aop.framework.AbstractSingletonProxyFactoryBean.getProxy(AbstractSingletonProxyFactoryBean.java:187)
at org.springframework.aop.framework.AbstractSingletonProxyFactoryBean.afterPropertiesSet(AbstractSingletonProxyFactoryBean.java:159)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1202)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1172)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:428)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:251)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:156)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:248)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:160)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:284)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:352)
at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:244)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:187)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:49)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3827)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4334)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:525)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:920)
at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:883)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:492)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1138)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(H