IndexOutOfBoundsException when opening bpmn process

!ENTRY org.drools.eclipse 4 120 2012-05-24 11:26:34.402
!MESSAGE Internal error in Drools Plugin:
!STACK 0
java.lang.IndexOutOfBoundsException: Index: 2, Size: 2
at java.util.ArrayList.RangeCheck(ArrayList.java:547)
at java.util.ArrayList.get(ArrayList.java:322)
at org.drools.eclipse.flow.bpmn2.editor.BPMNModelEditor.refreshPalette(BPMNModelEditor.java:120)
at org.drools.eclipse.flow.bpmn2.editor.BPMNModelEditor.setInput(BPMNModelEditor.java:108)
at org.eclipse.gef.ui.parts.GraphicalEditor.init(GraphicalEditor.java:346)
at org.eclipse.ui.internal.EditorManager.createSite(EditorManager.java:828)
at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:647)
at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:465)
at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:595)
at org.eclipse.ui.internal.PartPane.setVisible(PartPane.java:313)
at org.eclipse.ui.internal.presentations.PresentablePart.setVisible(PresentablePart.java:180)
at org.eclipse.ui.internal.presentations.util.PresentablePartFolder.select(PresentablePartFolder.java:270)
at org.eclipse.ui.internal.presentations.util.LeftToRightTabOrder.select(LeftToRightTabOrder.java:65)
at org.eclipse.ui.internal.presentations.util.TabbedStackPresentation.selectPart(TabbedStackPresentation.java:473)
at org.eclipse.ui.internal.PartStack.refreshPresentationSelection(PartStack.java:1245)
at org.eclipse.ui.internal.PartStack.setSelection(PartStack.java:1198)
at org.eclipse.ui.internal.PartStack.showPart(PartStack.java:1597)
at org.eclipse.ui.internal.PartStack.add(PartStack.java:493)
at org.eclipse.ui.internal.EditorStack.add(EditorStack.java:103)
at org.eclipse.ui.internal.PartStack.add(PartStack.java:479)
at org.eclipse.ui.internal.EditorStack.add(EditorStack.java:112)
at org.eclipse.ui.internal.EditorSashContainer.addEditor(EditorSashContainer.java:63)
at org.eclipse.ui.internal.EditorAreaHelper.addToLayout(EditorAreaHelper.java:225)
at org.eclipse.ui.internal.EditorAreaHelper.addEditor(EditorAreaHelper.java:213)
at org.eclipse.ui.internal.EditorManager.createEditorTab(EditorManager.java:808)
at org.eclipse.ui.internal.EditorManager.openEditorFromDescriptor(EditorManager.java:707)
at org.eclipse.ui.internal.EditorManager.openEditor(EditorManager.java:666)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditorBatched(WorkbenchPage.java:2942)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:2850)
at org.eclipse.ui.internal.WorkbenchPage.access$11(WorkbenchPage.java:2842)
at org.eclipse.ui.internal.WorkbenchPage$10.run(WorkbenchPage.java:2793)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2789)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2773)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2764)
at org.eclipse.ui.ide.IDE.openEditor(IDE.java:651)
at org.eclipse.ui.ide.IDE.openEditor(IDE.java:610)
at org.eclipse.jdt.internal.ui.javaeditor.EditorUtility.openInEditor(EditorUtility.java:355)
at org.eclipse.jdt.internal.ui.javaeditor.EditorUtility.openInEditor(EditorUtility.java:164)
at org.eclipse.jdt.ui.actions.OpenAction.run(OpenAction.java:249)
at org.eclipse.jdt.ui.actions.OpenAction.run(OpenAction.java:228)
at org.eclipse.jdt.ui.actions.SelectionDispatchAction.dispatchRun(SelectionDispatchAction.java:275)
at org.eclipse.jdt.ui.actions.SelectionDispatchAction.run(SelectionDispatchAction.java:251)
at org.eclipse.jdt.internal.ui.packageview.PackageExplorerActionGroup.handleOpen(PackageExplorerActionGroup.java:376)
at org.eclipse.jdt.internal.ui.packageview.PackageExplorerPart$4.open(PackageExplorerPart.java:538)
at org.eclipse.ui.OpenAndLinkWithEditorHelper$InternalListener.open(OpenAndLinkWithEditorHelper.java:48)
at org.eclipse.jface.viewers.StructuredViewer$2.run(StructuredViewer.java:866)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
at org.eclipse.jface.viewers.StructuredViewer.fireOpen(StructuredViewer.java:864)
at org.eclipse.jface.viewers.StructuredViewer.handleOpen(StructuredViewer.java:1152)
at org.eclipse.jface.viewers.StructuredViewer$6.handleOpen(StructuredViewer.java:1256)
at org.eclipse.jface.util.OpenStrategy.fireOpenEvent(OpenStrategy.java:275)
at org.eclipse.jface.util.OpenStrategy.access$2(OpenStrategy.java:269)
at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:309)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1258)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1282)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1267)
at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1061)
at org.eclipse.swtbot.swt.finder.widgets.AbstractSWTBot$2.run(AbstractSWTBot.java:159)
at org.eclipse.swtbot.swt.finder.finders.UIThreadRunnable$5.doRun(UIThreadRunnable.java:221)
at org.eclipse.swtbot.swt.finder.finders.UIThreadRunnable$1.run(UIThreadRunnable.java:89)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:135)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:3563)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3212)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2701)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2665)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2499)
at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:679)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:668)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:123)
at org.eclipse.swtbot.eclipse.core.UITestApplication.start(UITestApplication.java:54)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:344)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
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:597)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
at org.eclipse.equinox.launcher.Main.main(Main.java:1386)