Index: wp-admin/includes/post.php
===================================================================
--- wp-admin/includes/post.php	(revision 15819)
+++ wp-admin/includes/post.php	(working copy)
@@ -1130,7 +1130,7 @@
 		return false;
 
 	$lock = get_post_meta( $post->ID, '_edit_lock', true );
-	$last = get_post_meta( $post->ID, '_edit_last', true );
+	$last = get_post_meta( $post->ID, '_edit_lock_user', true );
 
 	$time_window = apply_filters( 'wp_check_post_lock_window', AUTOSAVE_INTERVAL * 2 );
 
@@ -1156,6 +1156,7 @@
 	$now = time();
 
 	update_post_meta( $post->ID, '_edit_lock', $now );
+	update_post_meta( $post->ID, '_edit_lock_user', get_current_user_id() );
 }
 
 /**
@@ -1166,8 +1167,8 @@
  */
 function _admin_notice_post_locked() {
 	global $post;
-	$last_user = get_userdata( get_post_meta( $post->ID, '_edit_last', true ) );
-	$last_user_name = $last_user ? $last_user->display_name : __('Somebody');
+	$lock_user = get_userdata( get_post_meta( $post->ID, '_edit_lock_user', true ) );
+	$lock_user_name = $lock_user ? $lock_user->display_name : __('Somebody');
 
 	switch ($post->post_type) {
 		case 'post':
@@ -1180,7 +1181,7 @@
 			$message = __( 'Warning: %s is currently editing this.' );
 	}
 
-	$message = sprintf( $message, esc_html( $last_user_name ) );
+	$message = sprintf( $message, esc_html( $lock_user_name ) );
 	echo "<div class='error'><p>$message</p></div>";
 }