When I enter a title for a new post or page, permalink address appears under the title as expected. It has the format "Permalink: (permalink address) Edit". My blog's character set is windows-1254 and I am using a Turkish language pack based on windows-1254 encoding. The Turkish word for "Edit" is "Düzenle" that includes the special character "ü". When the permalink appears, the word "Düzenle" appears as "D?". I saw that it is due to a character set encoding problem. When the new permalink is calculated, Ajax gets the information from the server and displays on the browser. However, the information is sent without character set info, so browser displays the special characters wrongly (i think browser assumes that character set is utf8, but it is windows-1254). I saw that adding a single line to admin-ajax.php solves the problem. Add
header('Content-Type: text/html; charset=' . get_option('blog_charset') );
after the line
$slug = isset($_POST['new_slug'])? $_POST['new_slug'] : '';
