.htaccess文件无限期地加载页面？

Question

我正在使用以下.htaccess，以便/cn/前面的页面加载http（其余部分加载https：

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /

# http requests anything other than /cn should become https
RewriteCond %{HTTPS} off
RewriteRule !^cn(/.*)?$ https://%{HTTP_HOST}%{REQUEST_URI} [R=302,NC,L,NE]

# https requests for /cn should become http
RewriteCond %{HTTPS} on
RewriteRule ^cn(/.*)?$ http://%{HTTP_HOST}%{REQUEST_URI} [R=302,NC,L,NE]

RewriteRule ^index\.php$ - [L]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . index.php [L]
</IfModule>

php_value upload_max_filesize    110M
php_value post_max_size          110M

奇怪的是页面只是永远加载。可能导致这种情况的原因是什么？