Nginx double requests for my upstreams?

[funkdoobiest]

My nginx-version:

nginx version: nginx/0.7.59
built by gcc 4.3.2 (Debian 4.3.2-1.1) 
configure arguments: --with-http_ssl_module --with-http_realip_module --with-http_addition_module --with-http_sub_module --with-http_stub_status_module --user=www-data --group=www-data

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,2644,3287#msg-3287