Index: modules/node.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/node.module,v
retrieving revision 1.650
diff -u -p -r1.650 node.module
--- modules/node.module	18 May 2006 14:58:57 -0000	1.650
+++ modules/node.module	23 May 2006 01:45:00 -0000
@@ -386,6 +386,8 @@ function node_load($param = array(), $re
         $node->$key = $value;
       }
     }
+
+    drupal_set_cache_date($node->changed);
   }
 
   if ($cachable) {
Index: modules/comment.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/comment.module,v
retrieving revision 1.459
diff -u -p -r1.459 comment.module
--- modules/comment.module	20 May 2006 08:14:09 -0000	1.459
+++ modules/comment.module	23 May 2006 01:45:01 -0000
@@ -296,7 +296,9 @@ function comment_form_alter($form_id, &$
 function comment_nodeapi(&$node, $op, $arg = 0) {
   switch ($op) {
     case 'load':
-      return db_fetch_array(db_query("SELECT last_comment_timestamp, last_comment_name, comment_count FROM {node_comment_statistics} WHERE nid = %d", $node->nid));
+      $comment = db_fetch_array(db_query("SELECT last_comment_timestamp, last_comment_name, comment_count FROM {node_comment_statistics} WHERE nid = %d", $node->nid));
+      drupal_set_cache_date($comment['last_comment_timestamp']);
+      return $comment;
       break;
 
     case 'prepare':
Index: includes/bootstrap.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/bootstrap.inc,v
retrieving revision 1.99
diff -u -p -r1.99 bootstrap.inc
--- includes/bootstrap.inc	7 May 2006 00:08:36 -0000	1.99
+++ includes/bootstrap.inc	23 May 2006 01:45:01 -0000
@@ -323,7 +323,7 @@ function cache_get($key) {
     variable_set('cache_flush', 0);
   }
 
-  $cache = db_fetch_object(db_query("SELECT data, created, headers, expire FROM {cache} WHERE cid = '%s'", $key));
+  $cache = db_fetch_object(db_query("SELECT data, created, timestamp, headers, expire FROM {cache} WHERE cid = '%s'", $key));
   if (isset($cache->data)) {
     // If the data is permanent or we're not enforcing a minimum cache lifetime
     // always return the cached data.
@@ -369,9 +369,9 @@ function cache_get($key) {
  */
 function cache_set($cid, $data, $expire = CACHE_PERMANENT, $headers = NULL) {
   db_lock_table('cache');
-  db_query("UPDATE {cache} SET data = %b, created = %d, expire = %d, headers = '%s' WHERE cid = '%s'", $data, time(), $expire, $headers, $cid);
+  db_query("UPDATE {cache} SET data = %b, created = %d, timestamp = %d, expire = %d, headers = '%s' WHERE cid = '%s'", $data, time(), drupal_get_cache_date(), $expire, $headers, $cid);
   if (!db_affected_rows()) {
-    @db_query("INSERT INTO {cache} (cid, data, created, expire, headers) VALUES ('%s', %b, %d, %d, '%s')", $cid, $data, time(), $expire, $headers);
+    @db_query("INSERT INTO {cache} (cid, data, created, timestamp, expire, headers) VALUES ('%s', %b, %d, %d, '%s')", $cid, $data, time(), drupal_get_cache_date(), $expire, $headers);
   }
   db_unlock_tables();
 }
@@ -503,13 +503,13 @@ function drupal_page_header() {
     if ($cache = page_get_cache()) {
       bootstrap_invoke_all('init');
       // Set default values:
-      $date = gmdate('D, d M Y H:i:s', $cache->created) .' GMT';
+      $date = gmdate('D, d M Y H:i:s', $cache->timestamp) .' GMT';
       $etag = '"'. md5($date) .'"';
 
       // Check http headers:
       $modified_since = isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) ? $_SERVER['HTTP_IF_MODIFIED_SINCE'] == $date : NULL;
       if (!empty($_SERVER['HTTP_IF_MODIFIED_SINCE']) && ($timestamp = strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE'])) > 0) {
-        $modified_since = $cache->created <= $timestamp;
+        $modified_since = $cache->timestamp <= $timestamp;
       }
       else {
         $modified_since = NULL;
@@ -549,7 +549,7 @@ function drupal_page_header() {
     }
     else {
       header("Expires: Sun, 19 Nov 1978 05:00:00 GMT");
-      header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
+      header("Last-Modified: " . gmdate("D, d M Y H:i:s", drupal_get_cache_date()) . " GMT");
       header("Cache-Control: no-store, no-cache, must-revalidate");
       header("Cache-Control: post-check=0, pre-check=0", false);
       header("Pragma: no-cache");
@@ -558,6 +558,34 @@ function drupal_page_header() {
 }
 
 /**
+ * Set cache date
+ */
+function drupal_set_cache_date($date = 0) {
+  static $cache_date = 0;
+
+  if ($date > $cache_date) {
+    $cache_date = $date;
+  }
+
+  return $cache_date;
+}
+
+/**
+ * Get cache date
+ */
+function drupal_get_cache_date() {
+  $date = drupal_set_cache_date();
+  $time = time();
+
+  if ($date < $time && $date > 0) {
+    return $date;
+  }
+  else {
+    return $time;
+  }
+}
+
+/**
  * Define the critical hooks that force modules to always be loaded.
  */
 function bootstrap_hooks() {