diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc
index 25dd3e6..6ef4e01 100644
--- a/includes/bootstrap.inc
+++ b/includes/bootstrap.inc
@@ -106,6 +106,12 @@ define('DRUPAL_ANONYMOUS_RID', 1);
 define('DRUPAL_AUTHENTICATED_RID', 2);
 
 /**
+ * The maximum time to allow for a lock to be held when rebuilding a page for 
+ * the page cache -- this is to prevent stale locks from aborted sessions.
+ */
+define('CACHE_REBUILD_MAX', 5);
+
+/**
  * Start the timer with the specified name. If you start and stop
  * the same timer multiple times, the measured intervals will be
  * accumulated.
@@ -475,6 +481,17 @@ function page_get_cache() {
   if (!$user->uid && $_SERVER['REQUEST_METHOD'] == 'GET' && count(drupal_set_message()) == 0) {
     $cache = cache_get($base_root . request_uri(), 'cache_page');
 
+    // Check if the currently cached page was created before the cache was
+    // last flushed.  If so, try to rebuild it.
+    if (is_object($cache) && $cache->created < variable_get('cache_page_clear', 0)) {
+      $lock = cache_get($base_root . request_uri(), 'cache_lock');
+      if (!$lock) {
+        // Grab the lock and rebuild the web page.
+        cache_set($base_root . request_uri(), 'cache_lock', time(), time() + CACHE_REBUILD_MAX);
+        $cache = NULL;
+      }
+    }
+
     if (empty($cache)) {
       ob_start();
     }
@@ -718,6 +735,9 @@ function request_uri() {
 function watchdog($type, $message, $severity = WATCHDOG_NOTICE, $link = NULL) {
   global $user, $base_root;
 
+  if (!function_exists('db_set_active')) {
+    include_once './includes/database.inc';
+  }
   $current_db = db_set_active();
 
   // Note: log the exact, entire absolute URL.
diff --git a/includes/common.inc b/includes/common.inc
index c0b08fa..bc95f38 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -1906,6 +1906,8 @@ function page_set_cache() {
       ob_end_flush();
       if ($cache && $data) {
         cache_set($base_root . request_uri(), 'cache_page', $data, CACHE_TEMPORARY, drupal_get_headers());
+        // Clear lock that prevented multiple requests rebuilding this page.
+        cache_clear_all($base_root . request_uri(), 'cache_lock');
       }
     }
   }
diff --git a/sites/all/modules/memcache/memcache.inc b/sites/all/modules/memcache/memcache.inc
index 2fe6df4..7d778c9 100644
--- a/sites/all/modules/memcache/memcache.inc
+++ b/sites/all/modules/memcache/memcache.inc
@@ -85,11 +85,13 @@ function cache_set($cid, $table = 'cache', $data, $expire = CACHE_PERMANENT, $he
  */
 function cache_clear_all($cid = NULL, $table = NULL, $wildcard = FALSE) {
   // If cid and table are not set, we should flush the cache_page table.
-  if (!isset($cid) && !isset($table)) {
-    $cid = '*';
-    $wildcard = TRUE;
-    $table = 'cache_page';
-  }
+  if ((!isset($cid) && !isset($table)) || $table == 'cache_page') {
+    // Special handling for the page cache.  Rather than flushing this table, we
+    // update a variable.  When pages are in high demand, this allows us to 
+    // serve the old cached version while an updated version is being created.
+    variable_set('cache_page_clear', time());
+    return;
+   }
   if (empty($cid) || ($cid == '*' && $wildcard !== TRUE)) {
     // don't do anything if cid is unset. this matches the default drupal behavior...
     if ($wildcard && $cid != '*') {