diff --git a/wp-includes/cache.php b/wp-includes/cache.php
index ecad5c6a4d..fee1a887d3 100644
--- a/wp-includes/cache.php
+++ b/wp-includes/cache.php
@@ -53,7 +53,7 @@ define('CACHE_SERIAL_FOOTER', "\n?".">");
 class WP_Object_Cache {
 	var $cache_dir;
 	var $cache_enabled = false;
-	var $expiration_time = 86400;
+	var $expiration_time = 900;
 	var $flock_filename = 'wp_object_cache.lock';
 	var $cache = array ();
 	var $dirty_objects = array ();
diff --git a/wp-includes/functions-post.php b/wp-includes/functions-post.php
index 2eb3a0d375..358ab3fe5a 100644
--- a/wp-includes/functions-post.php
+++ b/wp-includes/functions-post.php
@@ -121,7 +121,7 @@ function wp_insert_post($postarr = array()) {
 
 	if ($update) {
 		$wpdb->query(
-			"UPDATE $wpdb->posts SET
+			"UPDATE IGNORE $wpdb->posts SET
 			post_author = '$post_author',
 			post_date = '$post_date',
 			post_date_gmt = '$post_date_gmt',
@@ -143,7 +143,7 @@ function wp_insert_post($postarr = array()) {
 			WHERE ID = $post_ID");
 	} else {
 		$wpdb->query(
-			"INSERT INTO $wpdb->posts
+			"INSERT IGNORE INTO $wpdb->posts
 			(post_author, post_date, post_date_gmt, post_content, post_content_filtered, post_title, post_excerpt,  post_status, comment_status, ping_status, post_password, post_name, to_ping, pinged, post_modified, post_modified_gmt, post_parent, menu_order, post_mime_type)
 			VALUES
 			('$post_author', '$post_date', '$post_date_gmt', '$post_content', '$post_content_filtered', '$post_title', '$post_excerpt', '$post_status', '$comment_status', '$ping_status', '$post_password', '$post_name', '$to_ping', '$pinged', '$post_date', '$post_date_gmt', '$post_parent', '$menu_order', '$post_mime_type')");