java.lang.RuntimeException: org.apache.cxf.interceptor.Fault: org/apache/cxf/jaxrs/impl/ResponseImpl

The problem was occur not every time.
It was disappear after the Geronimo was restarted several times.

My webapp source code:
builder = Response.ok("just a test!");

The error stack:

2012-04-08 19:13:55,093 WARN [log] /favicon.ico
java.lang.RuntimeException: org.apache.cxf.interceptor.Fault: org/apache/cxf/jaxrs/impl/ResponseImpl
at org.apache.cxf.interceptor.AbstractFaultChainInitiatorObserver.onMessage(AbstractFaultChainInitiatorObserver.java:107)
at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:323)
at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:118)
at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:208)
at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:223)
at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:166)
at org.apache.cxf.transport.servlet.CXFNonSpringServlet.invoke(CXFNonSpringServlet.java:113)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.handleRequest(AbstractHTTPServlet.java:184)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doGet(AbstractHTTPServlet.java:112)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:575)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:163)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:546)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:483)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:228)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:956)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:411)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:188)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:891)
at org.apache.geronimo.jetty8.handler.GeronimoWebAppContext.doScope(GeronimoWebAppContext.java:240)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:247)
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:151)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:114)
at org.eclipse.jetty.server.Server.handle(Server.java:353)
at org.eclipse.jetty.server.HttpConnection.handleRequest(HttpConnection.java:598)
at org.eclipse.jetty.server.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:1059)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:590)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:212)
at org.eclipse.jetty.server.HttpConnection.handle(HttpConnection.java:427)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:510)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint.access$000(SelectChannelEndPoint.java:34)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:40)
at org.apache.geronimo.pool.ThreadPool$1.run(ThreadPool.java:243)
at org.apache.geronimo.pool.ThreadPool$ContextClassLoaderRunnable.run(ThreadPool.java:373)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)
Caused by: org.apache.cxf.interceptor.Fault: org/apache/cxf/jaxrs/impl/ResponseImpl
at org.apache.cxf.service.invoker.AbstractInvoker.createFault(AbstractInvoker.java:155)
at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:121)
at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:164)
at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:91)
at org.apache.cxf.interceptor.ServiceInvokerInterceptor$1.run(ServiceInvokerInterceptor.java:58)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at org.apache.cxf.workqueue.SynchronousExecutor.execute(SynchronousExecutor.java:37)
at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:106)
at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:263)
... 35 more
Caused by: java.lang.NoClassDefFoundError: org/apache/cxf/jaxrs/impl/ResponseImpl
at org.apache.cxf.jaxrs.impl.RuntimeDelegateImpl.createResponseBuilder(RuntimeDelegateImpl.java:80)
at javax.ws.rs.core.Response$ResponseBuilder.newInstance(Response.java:65)
at javax.ws.rs.core.Response.status(Response.java:270)
at javax.ws.rs.core.Response.ok(Response.java:233)
at com.cxf.rest.MyWebService.getFavicon(MyWebService.java:55)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.apache.cxf.service.invoker.AbstractInvoker.performInvocation(AbstractInvoker.java:173)
at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:89)
... 44 more
Caused by: java.lang.ClassNotFoundException: org.apache.cxf.jaxrs.impl.ResponseImpl
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:513)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:429)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:417)
at org.apache.geronimo.hook.equinox.GeronimoClassLoader.loadClass(GeronimoClassLoader.java:85)
at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
... 55 more