NPE when closing tab

Repoduction path:

• mvn clean jetty:run-war
• login and goto documents
• select "articles" folder
• select "myarticle1"
• click close tab
• select "myarticle1"
  Log shows: 30.03.2009 12:05:34 ERROR [org.apache.wicket.RequestCycle.logRuntimeException():1437] java.lang.NullPointerException

Complete Log:

[INFO] Starting jetty 6.1.10 ...
2009-03-30 11:53:06.211::INFO: jetty-6.1.10
2009-03-30 11:53:06.227::INFO: Extract jar:file:/C:/projects/hippo-ecm-trunk/quickstart/war/target/hippo-ecm-quickstart-war-2.05.01-SNAPSHOT.war!/ to C:\projec
ts\hippo-ecm-trunk\quickstart\war\target\work\webapp
2009-03-30 11:53:20.702::INFO: No Transaction manager found - if your webapp requires one, please configure one.
30.03.2009 11:53:43 WARN [org.hippoecm.repository.RepositoryServlet.init():161] Started an RMI registry on port 1099
2009-03-30 11:53:43.519::INFO: Started SelectChannelConnector@0.0.0.0:8080
[INFO] Started Jetty Server
[INFO] Starting scanner at interval of 5 seconds.
30.03.2009 12:05:22 WARN [org.hippoecm.frontend.editor.plugins.field.FieldPlugin.updateProvider():114] Unknown field body in type defaultcontent:article
30.03.2009 12:05:25 WARN [org.apache.wicket.markup.html.PackageResource.getResourceStream():560] Unable to find package resource [path = org/hippoecm/frontend/
plugins/reviewedactions/workflow-16.png, style = null, locale = null]
30.03.2009 12:05:25 WARN [org.apache.wicket.markup.html.PackageResource.getResourceStream():560] Unable to find package resource [path = org/hippoecm/frontend/
plugins/reviewedactions/workflow-16.png, style = null, locale = null]
30.03.2009 12:05:32 WARN [org.hippoecm.frontend.plugins.standards.browse.BrowseService.browse():128] Model null is not an JcrNodeModel
30.03.2009 12:05:34 WARN [org.hippoecm.frontend.plugin.impl.PluginManager.getReference():121] Referenced service was not registered
30.03.2009 12:05:34 ERROR [org.apache.wicket.RequestCycle.logRuntimeException():1437]
java.lang.NullPointerException
at org.hippoecm.frontend.plugins.cms.edit.CmsEditor.close(CmsEditor.java:108)
at org.hippoecm.frontend.plugins.cms.edit.EditorManagerPlugin.onEvent(EditorManagerPlugin.java:125)
at org.hippoecm.frontend.model.event.ObservableRegistry$ObservationContext.notifyObservers(ObservableRegistry.java:64)
at org.hippoecm.frontend.model.ModelReference.setModel(ModelReference.java:59)
at org.hippoecm.frontend.plugins.standards.browse.BrowseService$DocumentModelService.updateModel(BrowseService.java:51)
at org.hippoecm.frontend.plugins.standards.browse.BrowseService.updateDocumentModel(BrowseService.java:114)
at org.hippoecm.frontend.plugins.standards.browse.BrowseService.browse(BrowseService.java:121)
at org.hippoecm.frontend.plugins.standards.browse.BrowseService.selectDocument(BrowseService.java:106)
at org.hippoecm.frontend.plugins.standards.browse.BrowseService$DocumentModelService.setModel(BrowseService.java:56)
at org.hippoecm.frontend.plugins.standards.browse.BrowseService$DocumentModelService.setModel(BrowseService.java:43)
at org.hippoecm.frontend.plugins.standards.list.AbstractListingPlugin.selectionChanged(AbstractListingPlugin.java:147)
at org.hippoecm.frontend.plugins.standards.list.ListCell$1.onEvent(ListCell.java:50)
at org.apache.wicket.ajax.AjaxEventBehavior.respond(AjaxEventBehavior.java:163)
at org.apache.wicket.ajax.AbstractDefaultAjaxBehavior.onRequest(AbstractDefaultAjaxBehavior.java:297)
at org.apache.wicket.request.target.component.listener.BehaviorRequestTarget.processEvents(BehaviorRequestTarget.java:100)
at org.apache.wicket.request.AbstractRequestCycleProcessor.processEvents(AbstractRequestCycleProcessor.java:91)
at org.hippoecm.frontend.Main$6.processEvents(Main.java:270)
at org.apache.wicket.RequestCycle.processEventsAndRespond(RequestCycle.java:1175)
at org.apache.wicket.RequestCycle.step(RequestCycle.java:1252)
at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1353)
at org.apache.wicket.RequestCycle.request(RequestCycle.java:493)
at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:355)
at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:200)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
at org.hippoecm.frontend.plugins.login.ConcurrentLoginFilter.doFilter(ConcurrentLoginFilter.java:54)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:360)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:726)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:206)
at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:324)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:829)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:514)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:488)