diff --git a/src/gtkglue.c b/src/gtkglue.c
index 3a39f3c..b3f6938 100644
--- a/src/gtkglue.c
+++ b/src/gtkglue.c
@@ -403,10 +403,10 @@ button_update (GtkWidget * widget, GSGDialogElement * elem)
 {
   GSGDialog *dialog = elem->dialog;
   int opt_num = elem - dialog->element;
-  const SANE_Option_Descriptor *opt;
+//  const SANE_Option_Descriptor *opt;
   SANE_Word val = SANE_FALSE;
 
-  opt = sane_get_option_descriptor (dialog->dev, opt_num);
+//  opt = sane_get_option_descriptor (dialog->dev, opt_num);
   if (GTK_TOGGLE_BUTTON (widget)->active)
     val = SANE_TRUE;
   set_option (dialog, opt_num, &val, SANE_ACTION_SET_VALUE);
@@ -1420,12 +1420,16 @@ gsg_sync (GSGDialog * dialog)
       if (!SANE_OPTION_IS_ACTIVE (opt->cap))
 	continue;
 
-      if (opt->type != SANE_TYPE_INT && opt->type != SANE_TYPE_FIXED)
+      if ((opt->type != SANE_TYPE_INT) && (opt->type != SANE_TYPE_FIXED))
 	continue;
 
       if (opt->size == sizeof (SANE_Word))
 	continue;
 
+      // If curves is hidden (advanced option perhaps) then nothing to do.
+      if (!dialog->element[i].widget)
+	continue;
+
       /* ok, we're dealing with an active vector */
 
       optlen = opt->size / sizeof (SANE_Word);