Ho provato con altri browser ed esce sempre Fatal error.
Ho prova a creare un file .php con all'interno il codice:

<? include("http://dominio.com/index.php"); ?>

Il risultato:

Warning: include() [function.include]: URL file-access is disabled in the server configuration in /home/***/public_html/test.php on line 1

Warning: include(http://***/index.php) [function.include]: failed to open stream: no suitable wrapper could be found in /home/****/public_html/test.php on line 1

Warning: include() [function.include]: Failed opening 'http://****/index.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/****/public_html/test.php on line 1