从hibernate2升级3后出现的这个是什么错误啊

t sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
2008-11-06 17:27:54,156 WARN  (PojoEntityTuplizer.java:173) - could not create proxy factory for:com.syni.im800.model.ToInformuser
org.hibernate.HibernateException: CGLIB Enhancement failed: com.syni.im800.model.ToInformuser
at org.hibernate.proxy.CGLIBLazyInitializer.getProxyFactory(CGLIBLazyInitializer.java:132)
at org.hibernate.proxy.CGLIBProxyFactory.postInstantiate(CGLIBProxyFactory.java:41)
at org.hibernate.tuple.PojoEntityTuplizer.buildProxyFactory(PojoEntityTuplizer.java:161)
at org.hibernate.tuple.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:131)
at org.hibernate.tuple.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:55)
at org.hibernate.tuple.TuplizerLookup.create(TuplizerLookup.java:64)
at org.hibernate.tuple.EntityMetamodel.<init>(EntityMetamodel.java:257)
at org.hibernate.persister.entity.AbstractEntityPersister.<init>(AbstractEntityPersister.java:412)
at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:108)
at org.hibernate.persister.PersisterFactory.createClassPersister(PersisterFactory.java:55)
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:216)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1176)
at org.springframework.orm.hibernate3.LocalSessionFactoryBean.newSessionFactory(LocalSessionFactoryBean.java:800)
at org.springframework.orm.hibernate3.LocalSessionFactoryBean.afterPropertiesSet(LocalSessionFactoryBean.java:726)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1059)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:363)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:226)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:147)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:269)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:320)
at org.springframework.web.context.support.AbstractRefreshableWebApplicationContext.refresh(AbstractRefreshableWebApplicationContext.java:134)
at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:246)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:184)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:49)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3843)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4350)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
at org.apache.catalina.core.StandardService.start(StandardService.java:516)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
at org.apache.catalina.startup.Catalina.start(Catalina.java:578)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
Caused by: java.lang.NoSuchMethodError: net.sf.cglib.proxy.Enhancer.setInterceptDuringConstruction(Z)V
at org.hibernate.proxy.CGLIBLazyInitializer.getProxyFactory(CGLIBLazyInitializer.java:118)
... 38 more
2008-11-06 17:27:54,250 INFO  (SessionFactoryObjectFactory.java:82) - Not binding factory to JNDI, no JNDI name configured
2008-11-06 17:27:54,328 INFO  (HibernateTransactionManager.java:396) - Using DataSource [org.apache.tomcat.dbcp.dbcp.BasicDataSource@25b72a] of Hibernate SessionFactory for HibernateTransactionManager
2008-11-06 17:27:54,328 INFO  (HibernateTransactionManager.java:396) - Using DataSource [org.apache.tomcat.dbcp.dbcp.BasicDataSource@1c5cd7] of Hibernate SessionFactory for HibernateTransactionManager
2008-11-06 17:27:54,343 INFO  (AbstractBeanFactory.java:550) - Destroying singletons in factory {org.springframework.beans.factory.support.DefaultListableBeanFactory defining beans [csvDisplayProvider,excelDisplayProvider,classicLook,simpleLook,microsoftLook,dataSource,im800DataSource,sessionFactory,im800SessionFactory,transactionManager,im800TransactionManager,authregVdnDAO,vdnUserDAO,vdnSkillDAO,vdnDnDAO,announcementDAO,bulletinDAO,rollmessageDAO,basePropertyDAO,authregDAO,vcardDAO,vcardGroupDAO,activeDAO,xformsMDAO,categoryDAO,srclabelDAO,tmUserinfoDAO,toInformDAO,toInformuserDAO,toAskDAO,toSheetDAO,toSheetactioncDAO,toAuthregDAO,toIm800tagImgDAO,toStatusImgDAO,to2008-11-6 17:27:54 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 'authregVdnDAO' defined in ServletContext resource [/WEB-INF/config/applicationContext-hibernate.xml]: Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: net/sf/hibernate/Session
java.lang.NoClassDefFoundError: net/sf/hibernate/Session
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2427)
at java.lang.Class.getDeclaredMethods(Class.java:1791)
at java.beans.Introspector$1.run(Introspector.java:1272)