Segfault on Gtk::ListStore::clear ()

[Phil Wolff <adiabat centurylink net>]

Consider this Gtk::ListStore (in a Gtk::ComboBox, if that matters):

            Gtk::TreeIter iList = m_refServModel->get_iter( "0" );
            while ( iList ) {
                std::cout << (*iList)[m_cServings.m_sStdServ] << std::endl;
                ++iList;
            }
            m_refServModel->clear ();

The while() loop correctly displays the several items in the list, but 
the clear() generates a segfault.

Any insight would be appreciated!