Error while removing context

大家帮我看一下这个问题。当我用Struts2在Eclipse里部署一个项目的时候没有问题，但是每次Remove deployment的时候会报异常：2011-12-6 15:45:06 org.apache.catalina.startup.HostConfig checkResources
信息: Undeploying context [/0600_ActionWildcard]
2011-12-6 15:45:06 org.apache.catalina.startup.HostConfig checkResources
警告: Error while removing context [/0600_ActionWildcard]
java.lang.NoClassDefFoundError: org/apache/struts2/util/ObjectFactoryDestroyable
at org.apache.struts2.dispatcher.Dispatcher.cleanup(Dispatcher.java:263)
at org.apache.struts2.dispatcher.ng.PrepareOperations.cleanupDispatcher(PrepareOperations.java:179)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.destroy(StrutsPrepareAndExecuteFilter.java:100)
at org.apache.catalina.core.ApplicationFilterConfig.release(ApplicationFilterConfig.java:303)
at org.apache.catalina.core.StandardContext.filterStop(StandardContext.java:4227)
at org.apache.catalina.core.StandardContext.stopInternal(StandardContext.java:4914)
at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:214)
at org.apache.catalina.core.ContainerBase.removeChild(ContainerBase.java:921)
at org.apache.catalina.startup.HostConfig.checkResources(HostConfig.java:1269)
at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1455)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:338)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:89)
at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1186)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1340)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1349)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1329)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.ClassNotFoundException: org.apache.struts2.util.ObjectFactoryDestroyable
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1664)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1509)
... 18 more
2011-12-6 15:45:06 org.apache.catalina.startup.HostConfig checkResources
警告: Error during context [/0600_ActionWildcard] destroy
LifecycleException:  An invalid Lifecycle transition was attempted ([destroy]) for component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/0600_ActionWildcard]] in state [STOPPING]
at org.apache.catalina.util.LifecycleBase.invalidTransition(LifecycleBase.java:320)
at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:265)
at org.apache.catalina.startup.HostConfig.checkResources(HostConfig.java:1275)
at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1455)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:338)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:89)
at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1186)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1340)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1349)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1329)
at java.lang.Thread.run(Thread.java:662)
Struts2.2.3.1；Tomcat7.0.0。求解答，不胜感激。