When deleting a portlet the following stack trace is generated in the logs:

ERROR [http-8080-Processor25] portal.ChannelManager.[] Feb/13 17:31:18 - java.lang.IllegalStateException: No PortalControlStructures is associated with this IChannel, either no valid request has started or the request is complete.
java.lang.IllegalStateException: No PortalControlStructures is associated with this IChannel, either no valid request has started or the request is complete.
at org.jasig.portal.channels.portlet.CSpringPortletAdaptor.receiveEvent(CSpringPortletAdaptor.java:220)
at org.jasig.portal.ChannelManager.removeChannel(ChannelManager.java:898)
at org.jasig.portal.ChannelManager.channelDeleted(ChannelManager.java:1225)
at org.jasig.portal.layout.dlm.DistributedLayoutManager.deleteNode(DistributedLayoutManager.java:649)
at org.jasig.portal.layout.TransientUserLayoutManagerWrapper.deleteNode(TransientUserLayoutManagerWrapper.java:193)
at org.jasig.portal.layout.dlm.remoting.UpdatePreferencesServlet.doGet(UpdatePreferencesServlet.java:148)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
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.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
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:874)
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:689)
at java.lang.Thread.run(Thread.java:613)
 INFO [http-8080-Processor25] handlers.LoggingEventHandler.[] Feb/13 17:31:18 - Channel [Bookmarks, 231, u14l1n10] was removed from layout 1 by Admin User (admin) at Wed Feb 13 17:31:18 EST 2008