--- modules/system/system.module        2008-08-29 13:57:05.000000000 -0700
+++ modules/system/system.module        2008-09-01 12:50:19.000000000 -0700
@@ -918,6 +918,12 @@ function _system_theme_data() {
           $themes[$key]->prefix = $key;
         }
       }
+      // Check if the subtheme regions are empty. If so, and the basetheme 
+      // regions are not empty, load the base theme regions instead of defaults.
+      $themes_regions = drupal_parse_info_file($theme->filename);
+      if (!isset($themes_regions['regions']) && !empty($themes[$base_key]->info['regions'])) {
+        $themes[$key]->info['regions'] = $themes[$base_key]->info['regions'];
+      }
     }
 
     $themes_info = $themes;