it seems that i'm not the only one having this problem but i haven't understand how to solve it:
i worked on a local copy of my website, installed worpress, everything worked fine.
after i uploaded all the files and database on the web server i noticed that my admin panel only shows up in english and not in italian which is my language.
i did upload the files it_IT.mo and it_IT.po and i did setup the file wp-config.php adding define ('WPLANG', 'it_IT');
i emailed the hosting provider but they have no idea on how to solve this problem.
if anyone can help, it will be very appreciated