Ho messo il percorso assoluto come mi hai detto ma nulla, ora l'errore è un pò diverso:

Warning: include() [function.include]: URL file-access is disabled in the server configuration in /web/htdocs/www.sito.it/home/stonecration/lavabi.php on line 114

Warning: include(http://www.sito.it/stonecreation/cat...avabi.php?id=2) [function.include]: failed to open stream: no suitable wrapper could be found in /web/htdocs/www.sito.it/home/stonecration/lavabi.php on line 114

Warning: include() [function.include]: Failed opening 'http://www.sito.it/stonecreation/catalogo/prodotto_lavabi.php?id=2' for inclusion (include_path='.:/php5/lib/php/') in /web/htdocs/www.sito.it/home/stonecration/lavabi.php on line 114