Crash when closing a window

This happened when I closed gedit (or possibly when I opened, but it opened fullscreen so the docks mightve hid...):

Marshaling name_changed signal
Exception in Gtk# callback delegate
  Note: Applications can use GLib.ExceptionManager.UnhandledException to handle the exception.
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NullReferenceException: Object reference not set to an instance of an object
  at Docky.Windowing.WindowMatcher+<FindDesktopFileForWindowOrDefault>c__Iterator4.MoveNext () [0x00278] in /home/rdyer/branches/docky/Docky.Windowing/Windowing/WindowMatcher.cs:220
  at System.Collections.Generic.List`1[System.Object].AddEnumerable (IEnumerable`1 enumerable) [0x00000]
  at System.Collections.Generic.List`1[System.Object]..ctor (IEnumerable`1 collection) [0x00000]
  at System.Linq.Enumerable.ToList[String] (IEnumerable`1 source) [0x00000]
  at Docky.Windowing.WindowMatcher+<SetupWindow>c__AnonStorey8.<>m__9 (System.Object , System.EventArgs ) [0x00000] in /home/rdyer/branches/docky/Docky.Windowing/Windowing/WindowMatcher.cs:139
  at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (object,object[],System.Exception&)
  at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000]
  --- End of inner exception stack trace ---
  at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000]
  at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000]
  at System.Delegate.DynamicInvokeImpl (System.Object[] args) [0x00000]
  at System.MulticastDelegate.DynamicInvokeImpl (System.Object[] args) [0x00000]
  at System.Delegate.DynamicInvoke (System.Object[] args) [0x00000]
  at GLib.Signal.ClosureInvokedCB (System.Object o, GLib.ClosureInvokedArgs args) [0x00000]
  at GLib.SignalClosure.Invoke (GLib.ClosureInvokedArgs args) [0x00000]
  at GLib.SignalClosure.MarshalCallback (IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data) [0x00000]
   at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
   at GLib.SignalClosure.MarshalCallback(IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data)
   at Gtk.Application.gtk_main()
   at Gtk.Application.Run()
   at Docky.Docky.Main(System.String[] args) in /home/rdyer/branches/docky/Docky/Docky/Docky.cs:line 79
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose
Cairo.Context: called from finalization thread, programmer is missing a call to Dispose