editting a document which does not have a non-mandatory field results in a NPE

for example:

04.06.2008 13:40:15 ERROR [org.hippoecm.frontend.sa.template.plugins.field.PropertyFieldPlugin.newProvider():64] hippo:createdBy
04.06.2008 13:40:15 ERROR [org.hippoecm.frontend.sa.plugin.impl.PluginFactory.createPlugin():58]
at org.hippoecm.frontend.sa.model.ModelService.setModel(ModelService.java:60)
at org.hippoecm.frontend.plugins.standards.sa.perspective.Perspective.view(Perspective.java:71)
at org.hippoecm.frontend.plugins.cms.edit.sa.MultiEditorPlugin.view(MultiEditorPlugin.java:146)
at org.hippoecm.frontend.sa.plugins.reviewedactions.FullReviewedActionsWorkflowPlugin$1.execute(FullReviewedActionsWorkflowPlugin.java:65)
at org.hippoecm.frontend.sa.plugin.workflow.AbstractWorkflowPlugin$2.onClick(AbstractWorkflowPlugin.java:134)
at org.apache.wicket.ajax.markup.html.AjaxLink$1.onEvent(AjaxLink.java:65)
at org.apache.wicket.ajax.AjaxEventBehavior.respond(AjaxEventBehavior.java:161)
at org.apache.wicket.ajax.AbstractDefaultAjaxBehavior.onRequest(AbstractDefaultAjaxBehavior.java:288)
at org.apache.wicket.request.target.component.listener.BehaviorRequestTarget.processEvents(BehaviorRequestTarget.java:100)
at org.apache.wicket.request.AbstractRequestCycleProcessor.processEvents(AbstractRequestCycleProcessor.java:91)
at org.apache.wicket.RequestCycle.processEventsAndRespond(RequestCycle.java:1166)
at org.apache.wicket.RequestCycle.step(RequestCycle.java:1243)
at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1330)
at org.apache.wicket.RequestCycle.request(RequestCycle.java:493)
at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:358)
at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:194)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1065)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:365)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:185)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:689)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:391)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:146)
at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
at org.mortbay.jetty.Server.handle(Server.java:285)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:457)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:751)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:500)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:209)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:357)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:329)
at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:475)
Caused by: java.lang.NullPointerException
at org.hippoecm.frontend.sa.template.plugins.field.FieldPlugin$TemplateController.start(FieldPlugin.java:149)
at org.hippoecm.frontend.sa.template.plugins.field.FieldPlugin.updateProvider(FieldPlugin.java:80)
at org.hippoecm.frontend.sa.template.plugins.field.PropertyFieldPlugin.<init>(PropertyFieldPlugin.java:49)
... 49 more