Index: modules/block/block.admin.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/block/block.admin.inc,v
retrieving revision 1.14
diff -u -p -r1.14 block.admin.inc
--- modules/block/block.admin.inc	22 Dec 2007 23:24:24 -0000	1.14
+++ modules/block/block.admin.inc	4 Feb 2008 17:27:44 -0000
@@ -123,9 +123,10 @@ function _block_compare($a, $b) {
     return $status;
   }
   // Sort by region (in the order defined by theme .info file).
-  $place = $regions[$a['region']] - $regions[$b['region']];
-  if ($place) {
-    return $place;
+  if (!empty($a['region']) && !empty($b['region'])) {
+    if ($place = $regions[$a['region']] - $regions[$b['region']]) {
+      return $place;
+    }
   }
   // Sort by weight.
   $weight = $a['weight'] - $b['weight'];