Index: wp-includes/comment.php
===================================================================
--- wp-includes/comment.php	(revision 13467)
+++ wp-includes/comment.php	(working copy)
@@ -816,7 +816,7 @@
 	if ( !empty($stats) )
 		return $stats;
 
-	$count = wp_cache_get("comments-{$post_id}", 'counts');
+	$count = get_transient("comments-{$post_id}");
 
 	if ( false !== $count )
 		return $count;
@@ -845,7 +845,7 @@
 	}
 
 	$stats = (object) $stats;
-	wp_cache_set("comments-{$post_id}", $stats, 'counts');
+	set_transient("comments-{$post_id}", $stats);
 
 	return $stats;
 }