Index: modules/taxonomy/taxonomy.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/taxonomy/taxonomy.module,v
retrieving revision 1.477
diff -u -p -r1.477 taxonomy.module
--- modules/taxonomy/taxonomy.module	5 Jun 2009 05:23:57 -0000	1.477
+++ modules/taxonomy/taxonomy.module	12 Jun 2009 09:47:56 -0000
@@ -685,6 +685,10 @@ function taxonomy_preview_terms($node) {
           }
         }
       }
+      // Our taxonomy term has already been converted to an object, leave it as is
+      elseif (is_object($term)) {
+        $taxonomy[(int) $term->tid] = $term;
+      }
       // A 'Single select' field returns the term id.
       elseif ($term) {
         $taxonomy[$term] = taxonomy_term_load($term);