Whenever I produce a "page" in Wordpress, a hyperlink instantly will get added to the peak navigation and all sorts of pages are 404. Right now this can be a simple test site, while using standard theme and relevant plug ins: qtranslate and advanced custom fields. I've some custom templates however for "posts" and never "pages".

EDIT: Basically totally reset the permalink structure towards the default /?p=123, then my url is domain.com?page_id=15&lang=en which is still 404

EDIT2: .htaccess content

# 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

Wouldso would one start debugging this?