Index: includes/cache.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/cache.inc,v
retrieving revision 1.19
diff -u -p -r1.19 cache.inc
--- includes/cache.inc	18 Jun 2008 03:36:23 -0000	1.19
+++ includes/cache.inc	1 Jul 2008 22:13:19 -0000
@@ -102,7 +102,7 @@ function cache_get($cid, $table = 'cache
  */
 function cache_set($cid, $data, $table = 'cache', $expire = CACHE_PERMANENT, $headers = NULL) {
   $serialized = 0;
-  if (is_object($data) || is_array($data)) {
+  if (!is_string($data)) {
     $data = serialize($data);
     $serialized = 1;
   }