Someone

****Old Code***
       # load the main interface
        self.glade = gtk.glade.XML('%s/ubiquity.glade' % GLADEDIR)

This would instantiate a GTKNotebook with many subpages, and on one subpage a vbox called release_notes_vbox.
This vbox was then hidable be self.release_notes_vbox.hide()        

****New Code***
       # load the main interface
        self.glade = gtk.glade.XML('%s/ubiquity.glade' % GLADEDIR)

        #load stepWelcome
        welcomeglade = gtk.glade.XML('%s/stepWelcome.glade' % GLADEDIR, 'stepWelcome')
        stepWelcome  = welcomeglade.get_widget('stepWelcome')
        self.glade.get_widget("steps").prepend_page(stepWelcome)

        #load stepLanguage
        languageglade = gtk.glade.XML('%s/stepLanguage.glade' % GLADEDIR, 'stepLanguage')
        stepLanguage = languageglade.get_widget('stepLanguage')
        self.glade.get_widget("steps").prepend_page(stepLanguage)

The subpages are now manually loaded and prepended into the GTKNotebook.
That same function call to hide the vbox doesn't work now, claiming that
release_notes_vbox isn't an attribute of the top level.