Index: wp-admin/includes/class-wp-comments-list-table.php
===================================================================
--- wp-admin/includes/class-wp-comments-list-table.php	(revision 18872)
+++ wp-admin/includes/class-wp-comments-list-table.php	(working copy)
@@ -51,6 +51,8 @@
 
 		$search = ( isset( $_REQUEST['s'] ) ) ? $_REQUEST['s'] : '';
 
+		$post_type = ( isset( $_REQUEST['post_type'] ) ) ? $_REQUEST['post_type'] : '';
+
 		$user_id = ( isset( $_REQUEST['user_id'] ) ) ? $_REQUEST['user_id'] : '';
 
 		$orderby = ( isset( $_REQUEST['orderby'] ) ) ? $_REQUEST['orderby'] : '';
@@ -94,6 +96,7 @@
 			'type' => $comment_type,
 			'orderby' => $orderby,
 			'order' => $order,
+			'post_type' => $post_type
 		);
 
 		$_comments = get_comments( $args );