Index: includes/theme.inc
=========================
--- includes/theme.inc	Fri Sep 24 23:20:08 2010
+++ includes/theme.926784.inc	Wed Sep 29 22:14:16 2010
@@ -93,10 +93,10 @@
 
   // Find all our ancestor themes and put them in an array.
   $base_theme = array();
-  $ancestor = $theme;
-  while ($ancestor && isset($themes[$ancestor]->base_theme)) {
+  $ancestor = $themes[$theme]->base_theme;
+  while ($ancestor) {
+    $base_theme[] = $themes[$ancestor];
     $ancestor = $themes[$ancestor]->base_theme;
-    $base_theme[] = $themes[$ancestor];
   }
   _drupal_theme_initialize($themes[$theme], array_reverse($base_theme));