Странная реакция nginx на дос

user wwwrun www;
worker_processes 2;

#[ debug | info | notice | warn | error | crit ]
error_log /root/conf/log/error_log info;
pid /root/conf/log/nginx_pid;
events { worker_connections 5000; }

worker_rlimit_nofile 5000;

http {
#if cpu ok set to on
#gzip on;
sendfile on;
tcp_nopush on;
tcp_nodelay on;

#create /tml/nginx (0700 nobody)
#fastcgi_pass_request_body Off
client_body_temp_path /tmp/nginx;
client_max_body_size 10m;

include mime.types;
default_type application/octet-stream;
log_format main '$http_host $remote_addr - $remote_user [$time_local] "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" $request_time';
access_log /root/conf/log/access_log main;

keepalive_timeout 5;


root /root/nginx/html;
index index.php index.html index.htm;


#limit ip conn in for locations
#limit_zone one $binary_remote_addr 10m;
#limit_conn one 5;

#standart
include koi-win;
charset windows-1251;

fastcgi_hide_header X-Powered-By;
server_names_hash_bucket_size 64;

fastcgi_index index.php;
fastcgi_connect_timeout 60;
fastcgi_send_timeout 180;
fastcgi_read_timeout 180;
fastcgi_buffer_size 32k;
fastcgi_buffers 4 32k;
fastcgi_busy_buffers_size 32k;
fastcgi_temp_file_write_size 32k;
fastcgi_temp_path /tmp/nginxphp;

server_name_in_redirect off;

server {
listen 80;

set $root "/home";

root $root;
location ~ \.php$ {
fastcgi_pass unix:/tmp/php-wwwrun.sock;
fastcgi_param SCRIPT_FILENAME $root$fastcgi_script_name;
fastcgi_param PATH_TRANSLATED $root$fastcgi_script_name;
include fastcgi_params;
}


}