--- modules/taxonomy/taxonomy.module	2008-09-18 00:55:37.000000000 +1200
+++ modules/taxonomy/taxonomy.module	2008-10-03 16:16:15.000000000 +1300
@@ -588,9 +588,10 @@ function taxonomy_preview_terms($node) {
         }
       }
       // A 'Single select' field returns the term id.
-      elseif ($term) {
+      elseif (is_numeric($term)) {
         $taxonomy[$term] = taxonomy_get_term($term);
       }
+      // Else probably an object already. Leave it alone.
     }
   }
   return $taxonomy;