Index: includes/bootstrap.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/bootstrap.inc,v
retrieving revision 1.96.2.5
diff -u -p -r1.96.2.5 bootstrap.inc
--- includes/bootstrap.inc	3 Aug 2006 13:53:15 -0000	1.96.2.5
+++ includes/bootstrap.inc	4 Aug 2006 21:21:12 -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();
 }
@@ -511,13 +511,13 @@ function drupal_page_header() {
   if (variable_get('cache', 0) && $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;
@@ -560,7 +560,7 @@ 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");
@@ -568,6 +568,34 @@ 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 $time;
+  }
+}
+
+/**
  * Define the critical hooks that force modules to always be loaded.
  */
 function bootstrap_hooks() {
Index: modules/comment.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/Attic/comment.module,v
retrieving revision 1.455.2.7
diff -u -p -r1.455.2.7 comment.module
--- modules/comment.module	18 Jul 2006 10:46:24 -0000	1.455.2.7
+++ modules/comment.module	4 Aug 2006 21:21:13 -0000
@@ -275,6 +275,9 @@ function comment_form_alter($form_id, &$
  */
 function comment_nodeapi(&$node, $op, $arg = 0) {
   switch ($op) {
+    case 'view':
+      drupal_set_cache_date($node->last_comment_timestamp);
+      break;
     case 'load':
       return db_fetch_array(db_query("SELECT last_comment_timestamp, last_comment_name, comment_count FROM {node_comment_statistics} WHERE nid = %d", $node->nid));
       break;
Index: modules/node.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/Attic/node.module,v
retrieving revision 1.641.2.12
diff -u -p -r1.641.2.12 node.module
--- modules/node.module	26 Jul 2006 12:12:27 -0000	1.641.2.12
+++ modules/node.module	4 Aug 2006 21:21:14 -0000
@@ -517,6 +517,8 @@ function node_save(&$node) {
 function node_view($node, $teaser = FALSE, $page = FALSE, $links = TRUE) {
   $node = (object)$node;
 
+  drupal_set_cache_date($node->changed);
+
   // Remove the delimiter (if any) that separates the teaser from the body.
   // TODO: this strips legitimate uses of '<!--break-->' also.
   $node->body = str_replace('<!--break-->', '', $node->body);
Index: modules/tracker.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/Attic/tracker.module,v
retrieving revision 1.129
diff -u -p -r1.129 tracker.module
--- modules/tracker.module	17 Apr 2006 20:48:26 -0000	1.129
+++ modules/tracker.module	4 Aug 2006 21:21:14 -0000
@@ -97,6 +97,7 @@ function tracker_page($uid = 0) {
     $result = pager_query($sql, 25, 0, $sql_count);
   }
 
+  $latest = 0;
   while ($node = db_fetch_object($result)) {
     // Determine the number of comments:
     $comments = 0;
@@ -116,8 +117,12 @@ function tracker_page($uid = 0) {
       array('class' => 'replies', 'data' => $comments),
       t('%time ago', array('%time' => format_interval(time() - $node->last_post)))
     );
+
+    $latest = ($node->last_post > $latest) ? $node->last_post : $latest;
   }
 
+  drupal_set_cache_date($latest);
+
   $header = array(t('Type'), t('Post'), t('Author'), t('Replies'), t('Last post'));
 
   $output = '<div id="tracker">';