Index: wp-includes/post-template.php
===================================================================
--- wp-includes/post-template.php	(revision 18062)
+++ wp-includes/post-template.php	(working copy)
@@ -831,7 +831,7 @@
 			$output .= '<li class="pagenav">' . $r['title_li'] . '<ul>';
 
 		global $wp_query;
-		if ( is_page() || is_attachment() || $wp_query->is_posts_page )
+		if ( is_page() || is_attachment() || $wp_query->is_posts_page || ($wp_query->query_vars['post_type'] != 'post' && is_single()) )
 			$current_page = $wp_query->get_queried_object_id();
 		$output .= walk_page_tree($pages, $r['depth'], $current_page, $r);