Index: modules/forum.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/forum.module,v
retrieving revision 1.317
diff -u -p -r1.317 forum.module
--- modules/forum.module	8 Mar 2006 15:13:20 -0000	1.317
+++ modules/forum.module	8 Mar 2006 21:57:30 -0000
@@ -298,8 +298,9 @@ function forum_submit(&$node) {
       }
     }
     if ($node->tid && $node->shadow) {
+      // A shadow copy needs to be created. Retain existing term and add new term.
       $terms = array_keys(taxonomy_node_get_terms($node->nid));
-      if (!in_array($node->tid, $node->terms)) {
+      if (!in_array($node->tid, $terms)) {
         $terms[] = $node->tid;
       }
       $node->taxonomy = $terms;