Is gtkmm deleting stuff it shouldn't be deleting ??

[John Emmas <johne53 tiscali co uk>]

The following code crashes when built against gtkmm v2.24.4 (using MSVC) :-

        #include "gtkmm/main.h"
        #include "gtkmm/window.h"

        int main (int argc, char *argv[])
        {
          Gtk::Main    app (&argc, &argv);
          Gtk::Window  mainWnd;

                mainWnd.set_title("Hello World!");

                app.run( mainWnd );

                return 0;
        }

The crash occurs at shutdown, when object 'mainWnd' is getting destroyed 
(I believe "unrealized" is the gtkmm parlance).  OTOH if I modify 
function main() to look like this, the code doesn't crash any more:-

        int main (int argc, char *argv[])
        {
          Gtk::Main    app (&argc, &argv);
          Gtk::Window*  mainWnd = new Gtk::Window;

                mainWnd->set_title("Hello World!");

                app.run( *mainWnd );

                return 0;
        }

whereas if I add my own 'delete' statement, it crashes in the same way 
as before, while executing 'delete' :-

        int main (int argc, char *argv[])
        {
          Gtk::Main    app (&argc, &argv);
          Gtk::Window*  mainWnd = new Gtk::Window;

                mainWnd->set_title("Hello World!");

                app.run( *mainWnd );

                delete mainWnd;  // <--- now crashes here !
                return 0;
        }

This suggests to me that gtkmm is deleting objects somewhere (a) without 
knowing whether or not it created them;  and (b) without even knowing if 
they were created from the free store.  FWIW if I adapt the code to use 
pure GTK+ functionality the problem goes away (i.e. if the same program 
gets implemented using GTK+ instead of gtkmm).  I just wondered if this 
might ring any bells with anyone here??  Alarm bells, at least..!  ;-)  
Thanks.

John