Index: i18ntaxonomy.module
===================================================================
--- i18ntaxonomy.module	(revision 903)
+++ i18ntaxonomy.module	(working copy)
@@ -998,7 +998,16 @@
     $breadcrumb = array();
     $breadcrumb[] = l(t('Home'), NULL);
     $breadcrumb[] = l(tt("taxonomy:vocabulary:$vid:name", $vocabulary->name), 'forum');
-    drupal_set_breadcrumb($breadcrumb);
+
+    if ($variables['parents']) {
+      // note : array $variables['parents'] doesn't need to be reversed. reverse is already done by template_preprocess_forums() (modules/forum/forum.module)
+      foreach ($parents as $p) {
+        if ($p->tid != $variables['tid']) {
+          $breadcrumb[] = l(tt("taxonomy:term:$p->tid:name", $p->name), 'forum/'. $p->tid);
+        }
+      }
+    } 
+    drupal_set_breadcrumb($breadcrumb);   
   }
 }