Index: modules/system.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/system.module,v
retrieving revision 1.227
diff -u -r1.227 system.module
--- modules/system.module	25 Aug 2005 21:14:17 -0000	1.227
+++ modules/system.module	26 Aug 2005 08:31:18 -0000
@@ -402,6 +402,13 @@
       $regions = array_merge($engine_regions, $regions);
     }
 
+    if (count($regions) == 0) {
+      $regions = array(
+       'left' => t('left sidebar'),
+       'right' => t('right sidebar')
+      );
+    }
+
     $list[$theme] = $regions;
   }