Why carts library doesnt support polish dialectic signs???

[eluser]penta997[/eluser]
I was fixed a 4 records limit. I was only changed in config file :$config['sess_encrypt_cookie'] to False. But still i cant add items with polish signs.
I was changed var $product_name_rules in cart.php file to '\.\:\-_ a-z0-9///^[a-zA-ZąęćżźńłóśĄĆĘŁŃÓŚŹŻ\s]+$/';
But didnt work.