Index: modules/hs_taxonomy.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/hierarchical_select/modules/hs_taxonomy.module,v
retrieving revision 1.41
diff -u -F '^f' -r1.41 hs_taxonomy.module
--- modules/hs_taxonomy.module	28 Feb 2010 20:33:53 -0000	1.41
+++ modules/hs_taxonomy.module	1 Mar 2010 20:07:16 -0000
@@ -391,7 +391,7 @@ function hs_taxonomy_hierarchical_select
     return array(0);
   }
 
-  $terms = array_reverse(taxonomy_get_parents_all($item));
+  $terms = array_reverse(hs_taxonomy_get_parents_all($item));
   foreach ($terms as $term) {
     $lineage[] = $term->tid;
   }
@@ -399,6 +399,24 @@ function hs_taxonomy_hierarchical_select
 }
 
 /**
+ * Alternative version of taxonomy_get_parents_all(): instead of using all
+ * parents of a term (i.e. when multiple parents are being used), only the
+ * first is kept.
+ */
+function hs_taxonomy_get_parents_all($tid) {
+  $parents = array();
+  if ($tid) {
+    $parents[] = taxonomy_get_term($tid);
+    $n = 0;
+    while ($parent = taxonomy_get_parents($parents[$n]->tid)) {
+      $parents = array_merge($parents, array(reset($parent)));
+      $n++;
+    }
+  }
+  return $parents;
+}
+
+/**
  * Implementation of hook_hierarchical_select_valid_item().
  */
 function hs_taxonomy_hierarchical_select_valid_item($item, $params) {