junit4+spring测试求疑

最近在看junit4，打算把junit测试添加到项目中来，可是，在这期间发生了不愿看到的情况，虽然不影响spring测试，可看起来挺不爽，一大堆错误信息：
ERROR CGLIB Enhancement failed:某个bean
net.sf.cglib.core.CodeGenerationException: java.lang.reflect.InvocationTargetException-->null
at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:237)
at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:377)
at net.sf.cglib.proxy.Enhancer.createClass(Enhancer.java:317)
at org.hibernate.proxy.CGLIBLazyInitializer.getProxyFactory(CGLIBLazyInitializer.java:126)
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:806)
at org.springframework.orm.hibernate3.LocalSessionFactoryBean.buildSessionFactory(LocalSessionFactoryBean.java:724)
at org.springframework.orm.hibernate3.AbstractSessionFactoryBean.afterPropertiesSet(AbstractSessionFactoryBean.java:211)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1363)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1329)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:476)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:412)
at java.security.AccessController.doPrivileged(Native Method)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:383)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:271)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:268)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:170)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:463)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:717)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:376)
at org.springframework.test.AbstractSingleSpringContextTests.createApplicationContext(AbstractSingleSpringContextTests.java:216)
at org.springframework.test.AbstractSingleSpringContextTests.loadContextLocations(AbstractSingleSpringContextTests.java:192)
at org.springframework.test.AbstractSingleSpringContextTests.loadContext(AbstractSingleSpringContextTests.java:172)
at org.springframework.test.AbstractSpringContextTests.getContext(AbstractSpringContextTests.java:133)
at org.springframework.test.AbstractSingleSpringContextTests.setUp(AbstractSingleSpringContextTests.java:101)
at junit.framework.TestCase.runBare(TestCase.java:132)
at org.springframework.test.ConditionalTestCase.runBare(ConditionalTestCase.java:79)
at junit.framework.TestResult$1.protect(TestResult.java:110)
at junit.framework.TestResult.runProtected(TestResult.java:128)
at junit.framework.TestResult.run(TestResult.java:113)
at junit.framework.TestCase.run(TestCase.java:124)
at junit.framework.TestSuite.runTest(TestSuite.java:232)
at junit.framework.TestSuite.run(TestSuite.java:227)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:49)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.lang.reflect.InvocationTargetException
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 net.sf.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:384)
at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:219)
... 50 more
Caused by: java.lang.SecurityException: class "某个bean类$$EnhancerByCGLIB$$fc05ad99"'s signer information does not match signer information of other classes in the same package
at java.lang.ClassLoader.checkCerts(ClassLoader.java:807)
at java.lang.ClassLoader.preDefineClass(ClassLoader.java:488)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:626)
at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
... 56 more
2010-11-29 15:59:24,940 WARN could not create proxy factory for:某个bean类

在网上查了好多资料，都说是jar冲突，可是还是没能解决的了，哪位高手帮助下？