Crash when Switching from Metacity to Compiz

Moving from Metacity Window manager to Compiz window manager with the command "compiz --replace" or with the Compiz Fusion Switch causes Gnome-do to crash.

I am using latest version from LP:DO

Here is the debug information:

Marshaling composited_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.Interface.AutohideTracker.Dispose () [0x00000]
  at Docky.Interface.DockArea.Dispose () [0x00000]
  at Docky.Interface.DockWindow.Dispose () [0x00000]
  at Do.Core.Controller.UnsetTheme () [0x00000]
  at Do.Core.Controller.OnCompositingChanged (System.Object sender, System.EventArgs args) [0x00000]
  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 Do.Do.Main(System.String[] args)
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