Index: modules/taxonomy/taxonomy.module
===================================================================
--- modules/taxonomy/taxonomy.module	(revision 2132)
+++ modules/taxonomy/taxonomy.module	(working copy)
@@ -784,11 +784,13 @@
  */
 function taxonomy_get_parents_all($tid) {
   $parents = array();
-  if ($tid) {
-    $parents[] = taxonomy_get_term($tid);
+  if ($term = taxonomy_get_term($tid)) {
+    $parents[] = $term;
     $n = 0;
-    while ($parent = taxonomy_get_parents($parents[$n]->tid)) {
-      $parents = array_merge($parents, $parent);
+    while ($n < count($parents)) {
+   if ($parent = taxonomy_get_parents($parents[$n]->tid)) {
+       $parents = array_merge($parents, $parent);
+      }
       $n++;
     }
   }