Can't delete a notifier define in the pom

When we try to delete a notifier define in pom, we obtain this exception :

ognl.MethodFailedException: Method "removeNotifier" failed for object org.apache.maven.continuum.DefaultContinuum@1342a67 [javax.jdo.JDOUserException: Transient instances cant be deleted.]
at ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:796)
at ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:61)
at ognl.OgnlRuntime.callMethod(OgnlRuntime.java:819)
at ognl.ASTMethod.getValueBody(ASTMethod.java:75)
at ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:170)
at ognl.SimpleNode.getValue(SimpleNode.java:210)
at ognl.Ognl.getValue(Ognl.java:333)
at ognl.Ognl.getValue(Ognl.java:378)
at ognl.Ognl.getValue(Ognl.java:357)
at org.apache.maven.continuum.web.action.CallApplicationModel.execute(CallApplicationModel.java:72)
at org.codehaus.plexus.summit.pipeline.valve.ActionValve.invoke(ActionValve.java:67)
at org.codehaus.plexus.summit.pipeline.AbstractPipeline.invoke(AbstractPipeline.java:70)
at org.codehaus.plexus.summit.Summit.doGet(Summit.java:54)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:595)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:688)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:358)
at org.mortbay.jetty.servlet.WebApplicationHandler.dispatch(WebApplicationHandler.java:294)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:567)
at org.mortbay.http.HttpContext.handle(HttpContext.java:1807)
at org.mortbay.jetty.servlet.WebApplicationContext.handle(WebApplicationContext.java:525)
at org.mortbay.http.HttpContext.handle(HttpContext.java:1757)
at org.mortbay.http.HttpServer.service(HttpServer.java:879)
at org.mortbay.http.HttpConnection.service(HttpConnection.java:789)
at org.mortbay.http.HttpConnection.handleNext(HttpConnection.java:960)
at org.mortbay.http.HttpConnection.handle(HttpConnection.java:806)
at org.mortbay.http.SocketListener.handleConnection(SocketListener.java:218)
at org.mortbay.util.ThreadedServer.handle(ThreadedServer.java:331)
at org.mortbay.util.ThreadPool$PoolThread.run(ThreadPool.java:520)
/-- Encapsulated exception ------------\
javax.jdo.JDOUserException: Transient instances cant be deleted.
at org.jpox.AbstractPersistenceManager.internalDeletePersistent(AbstractPersistenceManager.java:1107)
at org.jpox.AbstractPersistenceManager.deletePersistent(AbstractPersistenceManager.java:1133)
at org.apache.maven.continuum.store.JdoContinuumStore.attachAndDelete(JdoContinuumStore.java:1225)
at org.apache.maven.continuum.store.JdoContinuumStore.removeNotifier(JdoContinuumStore.java:697)
at org.apache.maven.continuum.core.DefaultContinuumCore.removeNotifier(DefaultContinuumCore.java:189)
at org.apache.maven.continuum.DefaultContinuum.removeNotifier(DefaultContinuum.java:549)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:491)
at ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:785)
at ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:61)
at ognl.OgnlRuntime.callMethod(OgnlRuntime.java:819)
at ognl.ASTMethod.getValueBody(ASTMethod.java:75)
at ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:170)
at ognl.SimpleNode.getValue(SimpleNode.java:210)
at ognl.Ognl.getValue(Ognl.java:333)
at ognl.Ognl.getValue(Ognl.java:378)
at ognl.Ognl.getValue(Ognl.java:357)
at org.apache.maven.continuum.web.action.CallApplicationModel.execute(CallApplicationModel.java:72)
at org.codehaus.plexus.summit.pipeline.valve.ActionValve.invoke(ActionValve.java:67)
at org.codehaus.plexus.summit.pipeline.AbstractPipeline.invoke(AbstractPipeline.java:70)
at org.codehaus.plexus.summit.Summit.doGet(Summit.java:54)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:595)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:688)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:358)
at org.mortbay.jetty.servlet.WebApplicationHandler.dispatch(WebApplicationHandler.java:294)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:567)
at org.mortbay.http.HttpContext.handle(HttpContext.java:1807)
at org.mortbay.jetty.servlet.WebApplicationContext.handle(WebApplicationContext.java:525)
at org.mortbay.http.HttpContext.handle(HttpContext.java:1757)
at org.mortbay.http.HttpServer.service(HttpServer.java:879)
at org.mortbay.http.HttpConnection.service(HttpConnection.java:789)
at org.mortbay.http.HttpConnection.handleNext(HttpConnection.java:960)
at org.mortbay.http.HttpConnection.handle(HttpConnection.java:806)
at org.mortbay.http.SocketListener.handleConnection(SocketListener.java:218)
at org.mortbay.util.ThreadedServer.handle(ThreadedServer.java:331)
at org.mortbay.util.ThreadPool$PoolThread.run(ThreadPool.java:520)
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