Problem swapping GtkScrolledWindow contents on the fly

[Andrew Wood <ajwood theiet org>]

The following function is called to display a vbox, which is read from a 
glade file, in a scrollview.

If the  vbox or 'page' hasnt been displayed before then 
generalpageinitialised will be false.

There are other 'pages' in the app which are vboxes read from a glade 
file in the same way. The app always shows the vbox called rightpanevbox 
and it swaps this variable to point to the appropriate one read from glade.

The first time the function is called the page shows perfectly. The 
second time I get errors such as:

Showing General Page
doing gtk_container_remove

(a.out:21153): Gtk-CRITICAL **: gtk_container_remove: assertion 
`GTK_IS_WIDGET (widget)' failed
done gtk_container_remove


(a.out:21153): GLib-GObject-WARNING **: invalid unclassed pointer in 
cast to `GtkWidget'

(a.out:21153): Gtk-CRITICAL **: gtk_scrolled_window_add_with_viewport: 
assertion `GTK_IS_WIDGET (child)' failed


(a.out:21153): GLib-GObject-WARNING **: invalid unclassed pointer in 
cast to `GtkWidget'

(a.out:21153): Gtk-CRITICAL **: gtk_widget_show_all: assertion 
`GTK_IS_WIDGET (widget)' failed


I cant understand why its happy the first time its called but not on 
subsequent calls. If anyone can enlighten me Id be very grateful

Thanks


void showGeneralPage()
{
   g_print("Showing General Page\n");
   if (generalpageinitialised==false)
   {
       generalpage= glade_xml_get_widget(generalpagexml,"mainvbox");
       glade_xml_signal_autoconnect(generalpagexml);
       generalpageinitialised=true;
       
   }
  
   if (pagedisplayed!="INIT")
   {
      //a previous page is shown so we need to remove it first
       g_print("doing gtk_container_remove\n");
       gtk_container_remove (GTK_CONTAINER 
(rightpanescrollview),gtk_bin_get_child(GTK_BIN(rightpanescrollview)));
       g_print("done gtk_container_remove\n");
   }
   rightpanevbox=generalpage; //make generalpage the one currently on show
   pagedisplayed = "General";

                
gtk_scrolled_window_add_with_viewport(GTK_SCROLLED_WINDOW(rightpanescrollview),GTK_WIDGET(rightpanevbox));
   gtk_widget_show_all(GTK_WIDGET(rightpanevbox));
}