Index: includes/cache.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/cache.inc,v
retrieving revision 1.51
diff -u -r1.51 cache.inc
--- includes/cache.inc	1 Dec 2010 00:26:03 -0000	1.51
+++ includes/cache.inc	13 Feb 2011 02:52:15 -0000
@@ -392,7 +392,7 @@
     // timer. The cache variable is loaded into the $user object by _drupal_session_read()
     // in session.inc. If the data is permanent or we're not enforcing a minimum
     // cache lifetime always return the cached data.
-    if ($cache->expire != CACHE_PERMANENT && variable_get('cache_lifetime', 0) && $user->cache > $cache->created) {
+    if ($cache->expire != CACHE_PERMANENT && variable_get('cache_lifetime', 0) && $user->cache > ($cache->created + variable_get('cache_lifetime', 0))) {
       // This cache data is too old and thus not valid for us, ignore it.
       return FALSE;
     }