diff --git a/ds.field_ui.inc b/ds.field_ui.inc
index f62e7cd..0c41aff 100644
--- a/ds.field_ui.inc
+++ b/ds.field_ui.inc
@@ -345,7 +345,7 @@ function ds_field_ui_layout_change_validate($form, &$form_state) {
   }
 
   // Save the mappings so we can re-use in the submit callback.
-  $form_state['mappings'] = $mappings['new'];
+  $form_state['mappings'] = isset($mappings['new']) ? $mappings['new'] : array();
 }
 
 /**
diff --git a/js/ds.js b/js/ds.js
index 4da691f..d07d05c 100644
--- a/js/ds.js
+++ b/js/ds.js
@@ -207,6 +207,9 @@ Drupal.fieldUIDisplayOverview.ds.prototype = {
    */
   regionChange: function (region) {
 
+    // Replace dashes with underscores.
+    region = region.replace('-', '_');
+    
     this.$regionSelect.val(region);    
 
     var refreshRows = {};