Problemas com myfaces em uma enterprise application

eu consigo usar o myfaces no netbeans a partir de uma aplicacao web simples, sem problemas…
mas quando tento utilizar dentro de uma Enterprise Application eu tenho uma exception:
javax.servlet.ServletException
root cause:
java.lang.NullPointerException
no log do servidor eu tenho o seguinte:

[code][#|2007-04-02T12:18:53.148-0300|SEVERE|sun-appserver-pe9.0|javax.enterprise.system.container.web|_ThreadID=14;_ThreadName=httpWorkerThread-8080-1;_RequestID=9ddf2c4d-29ad-465c-8a39-c1f2510da02f;|ApplicationDispatcher[/post] Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.myfaces.taglib.core.ViewTag.doStartTag(ViewTag.java:78)
at org.apache.jsp.welcomeJSF_jsp._jspx_meth_f_view_0(welcomeJSF_jsp.java:107)
at org.apache.jsp.welcomeJSF_jsp._jspService(welcomeJSF_jsp.java:81)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:353)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:412)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:318)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:397)
at org.apache.catalina.core.ApplicationDispatcher.doInvoke(ApplicationDispatcher.java:850)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:697)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:532)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:465)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:353)
at com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:413)
at org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHandlerImpl.java:211)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:133)
at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:244)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:140)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:245)
at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:397)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:184)
at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:144)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:216)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:184)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:276)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:536)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:179)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:73)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:182)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at com.sun.enterprise.web.VirtualServerPipeline.invoke(VirtualServerPipeline.java:120)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:939)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:137)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:536)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:939)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:239)
at com.sun.enterprise.web.connector.grizzly.ProcessorTask.invokeAdapter(ProcessorTask.java:667)
at com.sun.enterprise.web.connector.grizzly.ProcessorTask.processNonBlocked(ProcessorTask.java:574)
at com.sun.enterprise.web.connector.grizzly.ProcessorTask.process(ProcessorTask.java:844)
at com.sun.enterprise.web.connector.grizzly.ReadTask.executeProcessorTask(ReadTask.java:287)
at com.sun.enterprise.web.connector.grizzly.ReadTask.doTask(ReadTask.java:212)
at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:252)
at com.sun.enterprise.web.connector.grizzly.WorkerThread.run(WorkerThread.java:75)
|#]

[#|2007-04-02T12:18:53.148-0300|WARNING|sun-appserver-pe9.0|javax.enterprise.resource.webcontainer.jsf.lifecycle|_ThreadID=14;_ThreadName=httpWorkerThread-8080-1;_RequestID=9ddf2c4d-29ad-465c-8a39-c1f2510da02f;|executePhase(RENDER_RESPONSE 6,com.sun.faces.context.FacesContextImpl@1baeec3) threw exception
javax.faces.FacesException: org.apache.jasper.JasperException: java.lang.NullPointerException
at com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:418)
at org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHandlerImpl.java:211)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:133)
at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:244)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:140)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:245)
at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:397)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:184)
at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:144)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:216)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:184)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:276)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:536)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:179)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:73)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:182)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at com.sun.enterprise.web.VirtualServerPipeline.invoke(VirtualServerPipeline.java:120)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:939)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:137)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:536)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:939)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:239)
at com.sun.enterprise.web.connector.grizzly.ProcessorTask.invokeAdapter(ProcessorTask.java:667)
at com.sun.enterprise.web.connector.grizzly.ProcessorTask.processNonBlocked(ProcessorTask.java:574)
at com.sun.enterprise.web.connector.grizzly.ProcessorTask.process(ProcessorTask.java:844)
at com.sun.enterprise.web.connector.grizzly.ReadTask.executeProcessorTask(ReadTask.java:287)
at com.sun.enterprise.web.connector.grizzly.ReadTask.doTask(ReadTask.java:212)
at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:252)
at com.sun.enterprise.web.connector.grizzly.WorkerThread.run(WorkerThread.java:75)
Caused by: org.apache.jasper.JasperException: java.lang.NullPointerException
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:382)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:412)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:318)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:397)
at org.apache.catalina.core.ApplicationDispatcher.doInvoke(ApplicationDispatcher.java:850)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:697)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:532)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:465)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:353)
at com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:413)
… 34 more
Caused by: java.lang.NullPointerException
at org.apache.myfaces.taglib.core.ViewTag.doStartTag(ViewTag.java:78)
at org.apache.jsp.welcomeJSF_jsp._jspx_meth_f_view_0(welcomeJSF_jsp.java:107)
at org.apache.jsp.welcomeJSF_jsp._jspService(welcomeJSF_jsp.java:81)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:353)
… 44 more
|#]

[#|2007-04-02T12:18:53.164-0300|SEVERE|sun-appserver-pe9.0|javax.enterprise.system.container.web|_ThreadID=14;_ThreadName=httpWorkerThread-8080-1;_RequestID=9ddf2c4d-29ad-465c-8a39-c1f2510da02f;|StandardWrapperValve[Faces Servlet]: Servlet.service() for servlet Faces Servlet threw exception
java.lang.NullPointerException
at org.apache.myfaces.taglib.core.ViewTag.doStartTag(ViewTag.java:78)
at org.apache.jsp.welcomeJSF_jsp._jspx_meth_f_view_0(welcomeJSF_jsp.java:107)
at org.apache.jsp.welcomeJSF_jsp._jspService(welcomeJSF_jsp.java:81)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:353)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:412)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:318)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:397)
at org.apache.catalina.core.ApplicationDispatcher.doInvoke(ApplicationDispatcher.java:850)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:697)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:532)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:465)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:353)
at com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:413)
at org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHandlerImpl.java:211)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:133)
at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:244)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:140)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:245)
at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:397)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:184)
at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:144)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:216)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:184)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:276)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:536)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:179)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:73)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:182)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at com.sun.enterprise.web.VirtualServerPipeline.invoke(VirtualServerPipeline.java:120)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:939)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:137)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:536)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:939)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:239)
at com.sun.enterprise.web.connector.grizzly.ProcessorTask.invokeAdapter(ProcessorTask.java:667)
at com.sun.enterprise.web.connector.grizzly.ProcessorTask.processNonBlocked(ProcessorTask.java:574)
at com.sun.enterprise.web.connector.grizzly.ProcessorTask.process(ProcessorTask.java:844)
at com.sun.enterprise.web.connector.grizzly.ReadTask.executeProcessorTask(ReadTask.java:287)
at com.sun.enterprise.web.connector.grizzly.ReadTask.doTask(ReadTask.java:212)
at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:252)
at com.sun.enterprise.web.connector.grizzly.WorkerThread.run(WorkerThread.java:75)
|#][/code]

como eu faço pra utilizar o myfaces numa enterprise application?