My nginx configuration works fine, but suddenly after some time (mostly days) he begins to answer 3x and the error occurs in the log below for all requests:

2012/09/13 17:15:35 [error] 26027#0: *4923 rewrite or internal redirection cycle while processing "/index.php", client: 201.26.2.XXX, server: www.XXX.com.br, request: "GET /checkout/cart/ HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm-xxx.sock:", host: "www.XXX.com.br", referrer: "http://www.XXX.com.br/product-xxx.html"


The error only after I reload nginx configuration with "/etc/init.d/nginx reload"

What can it be?

My host config:

server {
listen xxx.com.br:80 default;

server_name www.xxx.com.br *.xxx.com.br;
root /home/xxx/www/;


location ~ ^/(admin|index\.php/admin) {
rewrite / https://$host$request_uri permanent;
break;
}

rewrite ^/minify/([0-9]+)(/.*.(js|css))$ /lib/minify/m.php?f=$2&d=$1 last;
rewrite ^/skin/m/([0-9]+)(/.*.(js|css))$ /lib/minify/m.php?f=$2&d=$1 last;

location / {
index index.php index.html;
try_files $uri $uri/ @handler;
expires 30d;
}


location ^~ /app/ { deny all; }
location ^~ /includes/ { deny all; }
location ^~ /lib/ { deny all; }
location /lib/minify/ { allow all;}
location ^~ /media/downloadable/ { deny all; }
location ^~ /pkginfo/ { deny all; }
location ^~ /report/config.xml { deny all; }
location ^~ /var/ { deny all; }

location ~/(cron\.sh|cron\.php|mage)$ { deny all; }
location ^~ /app { deny all; }
location ^~ /includes { deny all; }
location ^~ /lib { deny all; }

location ^~ /downloader { deny all; }
location ^~ /errors/.*\.(xml|phtml)$ { deny all; }
location ^~ /media/customer { deny all; }
location ^~ /media/downloadable { deny all; }
location ^~ /pkginfo { deny all; }
location ^~ /shell { deny all; }
location ^~ /report/.*\.(xml|phtml)$ { deny all; }
location ^~ /var { deny all; }

location /. { ## Disable .htaccess and other hidden files
return 404;
}

location @handler { ## Magento uses a common front handler
rewrite / /index.php;
}

location ~ .php/ { ## Forward paths like /js/index.php/x.js to relevant handler
rewrite ^(.*.php)/ $1 last;
}

location ~ .php$ { ## Execute PHP scripts
if (!-e $request_filename) { rewrite / /index.php last; } ## Catch 404s that try_files miss

include /etc/nginx/naxsi.rules;

expires off; ## Do not cache dynamic content
fastcgi_pass unix:/var/run/php5-fpm-xxx.sock;
include fastcgi_params; ## See /etc/nginx/fastcgi_params
fastcgi_param HTTPS $http_https;
#fastcgi_param HTTPS off;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_param MAGE_RUN_TYPE store;
fastcgi_param MAGE_RUN_CODE $magesite_xxx;
break;
}
}