When I update my WP 2.X to 3.5.1, the Chinese permalink goes wrong ..
and it was fixed when edit .htaccess by changing it
AuthName "wp-admin/"
AuthUserFile "/home/userid/.htpasswds/public_html/passwd"
to
AuthName "wp-admin/"
AuthUserFile "/home/userid/.htpasswds/public_html/passwd"# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress
because it is needed since 3.0