Index: feeds/mappers/taxonomy.inc
===================================================================
RCS file: /cvs/drupal/contributions/modules/feeds/mappers/taxonomy.inc,v
retrieving revision 1.2
diff -u -r1.2 taxonomy.inc
--- feeds/mappers/taxonomy.inc	8 Jul 2010 17:19:16 -0000	1.2
+++ feeds/mappers/taxonomy.inc	13 Aug 2010 09:34:53 -0000
@@ -58,6 +58,7 @@
 
   if ($vocab->tags) {
     // Simply add a comma separated list to the node for a "tags" vocabulary.
+    $terms = array_merge($terms, explode(',', $node->taxonomy['tags'][$vocab->vid]));
     $node->taxonomy['tags'][$vocab->vid] = implode(',', $terms);
   }
   else {