Hi!
even though i state an error-page in my web.xml in case of a view expired exception i get the common stacktrace page as following:

java.lang.NullPointerException
 at com.sun.faces.lifecycle.RestoreViewPhase.execute(RestoreViewPhase.java:163)
 at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:248)
 at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:244)
 at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:502)
 at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1124)
 at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:178)
 at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
 at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:390)
 at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:517)
 at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1115)
 at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:361)
 at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
 at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
 at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
 at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:417)
 at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
 at org.mortbay.jetty.Server.handle(Server.java:324)
 at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:534)
 at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:879)
 at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:741)
 at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:213)
 at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:403)
 at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
 at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:522)

<context-param>
<param-name>org.ajax4jsf.handleViewExpiredOnClient</param-name>
<param-value>true</param-value>
</context-param>
<error-page>
<exception-type>javax.faces.application.ViewExpiredException</exception-type>
<location>login.xhtml</location>
</error-page>