Restoring a document with a link fails

• Create new news document
• edit document
• select link
• save
• publish and take offline a few times
• take offline
• show rev. history
• select one
• restore

-> error
19.10.2009 16:29:52 ERROR [org.apache.wicket.RequestCycle.logRuntimeException():1437] workflow exception
java.lang.RuntimeException: workflow exception
at org.hippoecm.addon.workflow.CompatibilityWorkflowPlugin$WorkflowAction.invoke(CompatibilityWorkflowPlugin.java:148)
at org.hippoecm.addon.workflow.StdWorkflow$1$1.onClick(StdWorkflow.java:58)
at org.hippoecm.addon.workflow.MenuLink.onClick(MenuLink.java:50)
at org.apache.wicket.ajax.markup.html.AjaxLink$1.onEvent(AjaxLink.java:65)
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.PluginRequestCycleProcessor.processEvents(PluginRequestCycleProcessor.java:31)
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.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.hippoecm.frontend.plugins.login.ConcurrentLoginFilter.doFilter(ConcurrentLoginFilter.java:54)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:857)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:565)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1509)
at java.lang.Thread.run(Unknown Source)
Caused by: javax.jcr.InvalidItemStateException: Item cannot be saved because it has beenmodified externally: node /
at org.apache.jackrabbit.core.ItemImpl.getTransientStates(ItemImpl.java:246)
at org.apache.jackrabbit.core.ItemImpl.save(ItemImpl.java:929)
at org.apache.jackrabbit.core.SessionImpl.save(SessionImpl.java:858)
at org.hippoecm.repository.decorating.SessionDecorator.save(SessionDecorator.java:202)
at org.hippoecm.repository.impl.SessionDecorator.save(SessionDecorator.java:159)
at org.hippoecm.repository.decorating.checked.SessionDecorator.save(SessionDecorator.java:227)
at org.hippoecm.addon.workflow.CompatibilityWorkflowPlugin$WorkflowAction.execute(CompatibilityWorkflowPlugin.java:163)
at org.hippoecm.addon.workflow.CompatibilityWorkflowPlugin$WorkflowAction.execute(CompatibilityWorkflowPlugin.java:155)
at org.hippoecm.addon.workflow.CompatibilityWorkflowPlugin$WorkflowAction.invoke(CompatibilityWorkflowPlugin.java:143)
... 29 more