Crash B3; Syntax searching.

Very destructive (error same as Bob's) Floating window is the syntax window.

I just constructed a clause and first Terminal Node (no attributes). Constructed second node as described and Crash!

2010-01-13 11:11:26.7302    1    Info    FloatingWindow    Floating window activated: LDLS4.FloatingWindow
2010-01-13 11:11:43.2251    9    Info    SyncManager    (Timed) Uploading 1 items.
2010-01-13 11:11:44.5612    9    Info    SyncManager        SUCCESS - { SyntaxSearch, urn:uuid:88c522d7-4df3-4e42-a41b-775be4c18c3b, Untitled Syntax Search, False }
2010-01-13 11:11:44.5612    9    Info    SyncManager    (1336ms) Uploading 1 items.
2010-01-13 11:11:44.5932    9    Info    SyncManager    (Timed) Downloading items.
2010-01-13 11:11:45.5553    9    Info    SyncManager    (962ms) Downloading items.
2010-01-13 11:12:27.9957    1    Info    IsWorkingControl    Showing IsWorkingControl soon (name  id 34380875)
2010-01-13 11:12:28.3407    1    Info    IsWorkingControl    Hiding IsWorkingControl (name  id 34380875)
2010-01-13 11:12:28.7037    1    Info    IsWorkingControl    Showing IsWorkingControl soon (name  id 34380875)
2010-01-13 11:12:29.0058    1    Info    IsWorkingControl    Hiding IsWorkingControl (name  id 34380875)
2010-01-13 11:12:34.0830    1    Info    IsWorkingControl    Showing IsWorkingControl soon (name  id 34380875)
2010-01-13 11:12:34.2811    1    Info    IsWorkingControl    Hiding IsWorkingControl (name  id 34380875)
2010-01-13 11:12:39.2563    1    Info    IsWorkingControl    Showing IsWorkingControl soon (name  id 34380875)
2010-01-13 11:12:39.5034    1    Info    IsWorkingControl    Hiding IsWorkingControl (name  id 34380875)
2010-01-13 11:12:43.4926    1    Error    OurApp    Unhandled exception: System.NullReferenceException: Object reference not set to an instance of an object.
   at Libronix.Utility.EnumerableUtility.ForEach[T](IEnumerable`1 seq, Action`1 fn)
   at LDLS4.Panels.SyntaxSearchPanel.SyntaxTextViewModel.RefreshUserInterface()
   at LDLS4.Panels.SyntaxSearchPanel.OptionGroupViewModel.QueryNode_PropertyChanged(Object sender, PropertyChangedEventArgs e)
   at System.ComponentModel.PropertyChangedEventHandler.Invoke(Object sender, PropertyChangedEventArgs e)
   at Libronix.Utility.NotifyPropertyChangedUtility.Raise(PropertyChangedEventHandler fn, Object sender, String strPropertyName)
   at Libronix.Utility.NotifyPropertyChangedBase.RaisePropertyChanged(String strName)
   at Libronix.DigitalLibrary.Syntax.SyntaxQueryObject.<.ctor>b__6(Object sender, PropertyChangedEventArgs e)
   at Libronix.Utility.NotifyPropertyChangedUtility.Raise(PropertyChangedEventHandler fn, Object sender, String strPropertyName)
   at Libronix.Utility.NotifyPropertyChangedBase.RaisePropertyChanged(String strName)
   at Libronix.DigitalLibrary.Syntax.TreeNode`1.RemoveChild(TreeNode`1 node)
   at Libronix.DigitalLibrary.Syntax.SyntaxQueryObjectUtility.UpdateNodeWithMorphReferences(SyntaxQueryObject node, MorphDataType morphology, List`1 seqStrMorphologyReferences, Boolean bNotEqual)
   at LDLS4.Panels.SyntaxSearchPanel.MorphTextBoxModel.WriteToQuery(SyntaxQueryObject queryNode)
   at LDLS4.Panels.SyntaxSearchPanel.SyntaxTextViewModel.Dispose(Boolean disposing)
   at LDLS4.Panels.SyntaxSearchPanel.OptionGroupViewModel.Dispose()
   at LDLS4.Panels.SyntaxSearchPanel.SyntaxSpecificsViewModel.<Dispose>b__0(OptionGroupViewModel og)
   at Libronix.Utility.EnumerableUtility.ForEach[T](IEnumerable`1 seq, Action`1 fn)
   at LDLS4.Panels.SyntaxSearchPanel.SyntaxSpecificsViewModel.Dispose()
   at LDLS4.Panels.SyntaxSearchPanel.SyntaxSearchViewModel.CloseCurrentSpecifics()
   at LDLS4.Panels.SyntaxSearchPanel.SyntaxSearchViewModel.RefreshSpecificsViewModel()
   at LDLS4.Panels.SyntaxSearchPanel.SyntaxSearchViewModel.set_SelectedNode(DisplaySyntaxQueryNode value)
   at LDLS4.Panels.SyntaxSearchPanel.SyntaxSearchViewModel.<get_DeselectNodeBehavior>b__0()
   at Libronix.Utility.Windows.Behavior.Execute()
   at Libronix.Utility.Windows.Behavior.Libronix.Utility.Windows.IBehavior.Execute(Object parameter)
   at Libronix.Utility.Windows.EventBehaviorBinding.OurEventHandler(Object sender, EventArgs e)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
   at System.Windows.Input.InputManager.ProcessStagingArea()
   at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
   at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
   at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
   at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
   at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Boolean isSingleParameter)
   at System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg)
   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
   at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
   at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.Run()
   at System.Windows.Application.RunDispatcher(Object ignore)
   at System.Windows.Application.RunInternal(Window window)
   at System.Windows.Application.Run(Window window)
   at System.Windows.Application.Run()
   at LDLS4.OurApp.InitializeAndRun(ReadOnlyCollection`1 listArgs, SingleInstanceManager sim)
   at LDLS4.OurApp.Main(String[] astrArgs)