Exception when clicking on the tomboy icon after upgrading to gtk+ 2.9 --

Unhandled Exception: System.Reflection.TargetInvocationException: Exception has
been thrown by the target of an invocation. ---> System.InvalidCastException:
Cannot cast from source type to destination type.
in <0x00055> Gtk.Widget:get_GdkWindow ()
in <0x00049> Tomboy.GuiUtils:GetMenuPosition (Gtk.Menu,int&,int&,bool&)
in <0x00063> (wrapper delegate-invoke)
System.MulticastDelegate:invoke_void_Menu_int&_int&_bool& (Gtk.Menu,int&,int&,bool&)
in <0x00068> GtkSharp.MenuPositionFuncWrapper:NativeCallback
(intptr,int&,int&,bool&,intptr)
in <0x00045> (wrapper native-to-managed)
GtkSharp.MenuPositionFuncWrapper:NativeCallback (intptr,int&,int&,bool&,intptr)
in (unmanaged) 0x1069963
in <0x00004> (wrapper managed-to-native) Gtk.Menu:gtk_menu_popup
(intptr,intptr,intptr,GtkSharp.MenuPositionFuncNative,intptr,uint,uint)
in <0x000de> Gtk.Menu:Popup
(Gtk.Widget,Gtk.Widget,Gtk.MenuPositionFunc,intptr,uint,uint)
in <0x001b4> Tomboy.GuiUtils:PopupMenu (Gtk.Menu,Gdk.EventButton)
in <0x00095> Tomboy.TomboyTray:ButtonPress (object,Gtk.ButtonPressEventArgs)
in (unmanaged) 0x80b4b8a
in <0x00004> (wrapper managed-to-native)
System.Reflection.MonoMethod:InternalInvoke (object,object[])
in <0x0008d> System.Reflection.MonoMethod:Invoke
(object,System.Reflection.BindingFlags,System.Reflection.Binder,object[],System.Globalization.CultureInfo)
--- End of inner exception stack trace ---

in <0x0010e> System.Reflection.MonoMethod:Invoke (System.Object obj,
BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[]
parameters, System.Globalization.CultureInfo culture)
in <0x0001a> System.Reflection.MethodBase:Invoke (System.Object obj,
System.Object[] parameters)
in <0x000ad> System.Delegate:DynamicInvokeImpl (System.Object[] args)
in <0x00028> System.MulticastDelegate:DynamicInvokeImpl (System.Object[] args)
in <0x0001a> System.MulticastDelegate:DynamicInvokeImpl (System.Object[] args)
in <0x0000e> System.Delegate:DynamicInvoke (System.Object[] args)
in <0x00175> GtkSharp.boolObjectEventButtonSignal:boolObjectEventButtonCallback
(IntPtr arg0, IntPtr arg1, Int32 key)
in (wrapper native-to-managed)
GtkSharp.boolObjectEventButtonSignal:boolObjectEventButtonCallback
(intptr,intptr,int)
in <0x00000> <unknown method>
in (wrapper managed-to-native) Gtk.Application:gtk_main ()
in <0x00007> Gtk.Application:Run ()
in <0x00007> Gnome.Program:Run ()
in <0x00044> Tomboy.Tomboy:StartTrayIcon ()
in <0x00152> Tomboy.Tomboy:Main (System.String[] args)


The obvious of "rebuild gtk-sharp" doesn't seem to have fixed it.