Index: wp-includes/comment.php
===================================================================
--- wp-includes/comment.php	(revision 7865)
+++ wp-includes/comment.php	(working copy)
@@ -725,6 +725,9 @@
 			break;
 		case 'approve':
 			$query = $wpdb->prepare("UPDATE $wpdb->comments SET comment_approved='1' WHERE comment_ID = %d LIMIT 1", $comment_id);
+			if ( get_option( 'comments_notify' ) == true ) {
+				wp_notify_postauthor( $comment_id );
+			}
 			break;
 		case 'spam':
 			$query = $wpdb->prepare("UPDATE $wpdb->comments SET comment_approved='spam' WHERE comment_ID = %d LIMIT 1", $comment_id);