When testing Liferay's sample-icefaces-sun-portlet and sample-icefaces-myfaces-portlet in Liferay 4.3.2, I often received the following stacktrace in the Tomcat console:

18:51:47,937 ERROR [[Blocking Servlet]:257] Servlet.service() for servlet Blocking Servlet threw exception
java.lang.RuntimeException: Query does not contain parameter named: ice.session
        at com.icesoft.faces.webapp.http.servlet.ServletRequestResponse.checkExistenceOf(ServletRequestResponse.java:224
)
        at com.icesoft.faces.webapp.http.servlet.ServletRequestResponse.getParameter(ServletRequestResponse.java:93)
        at com.icesoft.faces.webapp.http.core.IDVerifier.service(IDVerifier.java:23)
        at com.icesoft.faces.webapp.http.common.standard.PathDispatcherServer$Matcher.serviceOnMatch(PathDispatcherServe
r.java:50)
        at com.icesoft.faces.webapp.http.common.standard.PathDispatcherServer.service(PathDispatcherServer.java:19)
        at com.icesoft.faces.webapp.http.servlet.ThreadBlockingAdaptingServlet.service(ThreadBlockingAdaptingServlet.jav
a:19)
        at com.icesoft.faces.webapp.http.servlet.EnvironmentAdaptingServlet.service(EnvironmentAdaptingServlet.java:29)
        at com.icesoft.faces.webapp.http.servlet.MainSessionBoundServlet.service(MainSessionBoundServlet.java:109)
        at com.icesoft.faces.webapp.http.servlet.SessionDispatcher.service(SessionDispatcher.java:35)
        at com.icesoft.faces.webapp.http.servlet.PathDispatcher$Matcher.serviceOnMatch(PathDispatcher.java:52)
        at com.icesoft.faces.webapp.http.servlet.PathDispatcher.service(PathDispatcher.java:29)
        at com.icesoft.faces.webapp.http.servlet.MainServlet.service(MainServlet.java:98)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
        at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:691)
        at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:469)
        at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:364)
        at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:301)
        at com.icesoft.faces.webapp.xmlhttp.BlockingServlet.service(BlockingServlet.java:54)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:210)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:151)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:870)
        at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java
:665)
        at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
        at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
        at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:685)
        at java.lang.Thread.run(Thread.java:595)