If you try to save a new indexer profile in the HTTP Indexer and phpCMS does not have write permissions to the file parser/include/defaults_indexer.php, a php errormessage is printed:
Warning: fopen(/var/www/foo/bar/htdocs/parser/include/defaults_indexer.php) [function.fopen]: failed to open stream: Permission denied in /var/www/foo/bar/htdocs/parser/include/class.lib_indexer_universal_phpcms.php on line 82