Index: wp-includes/comment.php
===================================================================
--- wp-includes/comment.php	(revision 15270)
+++ wp-includes/comment.php	(working copy)
@@ -712,7 +712,7 @@
 	$args = wp_parse_args( $args, $defaults );
 
 	if ( '' === $args['per_page'] && get_option('page_comments') )
-		$args['per_page'] = get_query_var('comments_per_page');
+		$args['per_page'] = get_option('comments_per_page');
 	if ( empty($args['per_page']) ) {
 		$args['per_page'] = 0;
 		$args['page'] = 0;
@@ -739,8 +739,13 @@
 
 	$comtypewhere = ( 'all' != $args['type'] && isset($allowedtypes[$args['type']]) ) ? " AND comment_type = '" . $allowedtypes[$args['type']] . "'" : '';
 
+	if ( $args['max_depth'] > 1 )
+		$fromparent = ' AND comment_parent = 0';
+	else
+		$fromparent = '';
+
 	// Count comments older than this one
-	$oldercoms = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(comment_ID) FROM $wpdb->comments WHERE comment_post_ID = %d AND comment_parent = 0 AND comment_approved = '1' AND comment_date_gmt < '%s'" . $comtypewhere, $comment->comment_post_ID, $comment->comment_date_gmt ) );
+	$oldercoms = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(comment_ID) FROM $wpdb->comments WHERE comment_post_ID = %d" . $fromparent . " AND comment_approved = '1' AND comment_date_gmt < '%s'" . $comtypewhere, $comment->comment_post_ID, $comment->comment_date_gmt ) );
 
 	// No older comments? Then it's page #1.
 	if ( 0 == $oldercoms )