Here too.

I dug into the gnome-screensaver code and was able to produce a test case that demonstrates that the problem lies in Gtk, not gnome-screensaver:

#include <gtk/gtk.h>

static gboolean
show_status (gpointer user_data)
{
  GdkKeymap *keymap;

  keymap = gdk_keymap_get_default ();
  g_print ("caps: %d, num: %d\n",
           gdk_keymap_get_caps_lock_state (keymap),
           gdk_keymap_get_num_lock_state (keymap));

  return TRUE;
}

int
main (void)
{
  gtk_init (NULL, NULL);

  g_timeout_add (1000, show_status, NULL);

  gtk_main ();

  return 0;
}

I think we may need to sprinkle 

 if (KEYMAP_USE_XKB (keymap))
    get_xkb (keymap_x11);

In some of the getters (and call update_lock_state initially)

Created attachment 184995 [details] [review]
patch

Created attachment 184996 [details] [review]
slightly improved

The second patch is slightly better, it should get the initial numlock state right.