I found multiple occurrences of these exceptions in the logs of Component Showcase. I'm not sure how to reproduce this.

2009-07-21 23:13:19,500 ERROR [com.icesoft.faces.webapp.http.core.ReceiveSendUpdates] Exception occured during rendering on http://component-showcase-test.icefaces.org/component-showcase/block/send-receive-updates [/showcase.jspx]
javax.faces.FacesException
        at com.sun.faces.lifecycle.ApplyRequestValuesPhase.execute(ApplyRequestValuesPhase.java:107)
        at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:245)
        at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:110)
        at com.icesoft.faces.webapp.http.core.JsfLifecycleExecutor.apply(JsfLifecycleExecutor.java:18)
        at com.icesoft.faces.webapp.http.core.ReceiveSendUpdates.renderCycle(ReceiveSendUpdates.java:132)
        at com.icesoft.faces.webapp.http.core.ReceiveSendUpdates.service(ReceiveSendUpdates.java:74)
        at com.icesoft.faces.webapp.http.core.RequestVerifier.service(RequestVerifier.java:28)
        at com.icesoft.faces.webapp.http.common.standard.PathDispatcherServer.service(PathDispatcherServer.java:24)
        at com.icesoft.faces.webapp.http.servlet.BasicAdaptingServlet.service(BasicAdaptingServlet.java:16)
        at com.icesoft.faces.webapp.http.servlet.PathDispatcher.service(PathDispatcher.java:23)
        at com.icesoft.faces.webapp.http.servlet.SessionDispatcher.service(SessionDispatcher.java:47)
        at com.icesoft.faces.webapp.http.servlet.SessionVerifier.service(SessionVerifier.java:22)
        at com.icesoft.faces.webapp.http.servlet.PathDispatcher.service(PathDispatcher.java:23)
        at com.icesoft.faces.webapp.http.servlet.MainServlet.service(MainServlet.java:135)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
        at com.icesoft.faces.webapp.xmlhttp.BlockingServlet.service(BlockingServlet.java:56)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
        at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:81)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
        at org.jboss.web.tomcat.security.CustomPrincipalValve.invoke(CustomPrincipalValve.java:39)
        at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:159)
        at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:59)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
        at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:307)
        at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:385)
        at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:748)
        at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:678)
        at org.apache.jk.common.SocketConnection.runIt(ChannelSocket.java:871)
        at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
        at java.lang.Thread.run(Thread.java:595)
Caused by: java.lang.NullPointerException
        at com.icesoft.faces.context.FileResource.withOptions(FileResource.java:29)
        at com.icesoft.faces.component.outputresource.RegisteredResource.withOptions(OutputResource.java:389)
        at com.icesoft.faces.webapp.http.core.ResourceDispatcher.registerResource(ResourceDispatcher.java:67)
        at com.icesoft.faces.context.BridgeFacesContext.registerResource(BridgeFacesContext.java:621)
        at com.icesoft.faces.context.BridgeFacesContext.registerResource(BridgeFacesContext.java:613)
        at com.icesoft.faces.component.outputresource.OutputResource.getResource(OutputResource.java:85)
        at com.icesoft.faces.component.dataexporter.DataExporter.broadcast(DataExporter.java:247)
        at com.icesoft.faces.component.panelseries.UISeries$RowEvent.broadcast(UISeries.java:610)
        at com.icesoft.faces.component.panelseries.UISeries.broadcast(UISeries.java:275)
        at com.icesoft.faces.component.paneltabset.PanelTabSet.broadcast(PanelTabSet.java:318)
        at javax.faces.component.UIData.broadcast(UIData.java:677)
        at com.icesoft.faces.component.panelseries.UISeries.broadcast(UISeries.java:270)
        at com.icesoft.faces.component.paneltabset.PanelTabSet.broadcast(PanelTabSet.java:318)
        at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:269)
        at javax.faces.component.UIViewRoot.processDecodes(UIViewRoot.java:327)
        at com.sun.faces.lifecycle.ApplyRequestValuesPhase.execute(ApplyRequestValuesPhase.java:99)
        ... 36 more