I moved my website from apache to nginx and everything seems to be working as expected except (Well, I've only seen that error) when I try to create posts through the Atom publishing protocol which can be accesed via http://wordpressblog.com/wp-app.php, on apache it worked well but on nginx it gives me a 404 error, I think it's not only me because every other wordpress blog that is using nginx gives me that error.
I could only find this that could be semi-related to this error: http://core.trac.wordpress.org/ticket/7361 but it is a fix for apache and I can't make it work on nginx
Any ideas to fix it?
If you have a wordpress blog running on nginx I'd appreciate if you tell me if you can correctly access your wp-app.php file.
Note that I'm currently using php-cgi with nginx, Could php-fpm make it work?

I've also setup a dumb installation for testing purposes at http://test.is-gorgeo.us/wp-app.php here is it's php information: http://test.is-gorgeo.us/phpinfo.php with this nginx.conf file: http://pastebin.com/qeUvpGrk I don't know if it's useful but here is the content of the wp-app.php file: http://pastebin.com/dX0Kn18i