в браузере-клиенте (chrome) прописан ip http proxy (nginx)
на домене club по 3000 порту висит socket.io с поддержкой xhr-pooling и websockets и nginx для отдачи статики по 80 порту
все хорошо и отлично кешируется c 80 порта, xhr-pooling тоже работает отлично

Но как только переключаюсь на websockets , получаю в логи
==
[ 03/Jul/2013:11:50:17 +0400 ] - "CONNECT club:3000 HTTP/1.1" "400" "rt:0.018" "urt:-" "cache: -"



==== CONFIG
map $http_upgrade $connection_upgrade {
default upgrade;
'' close;
}

upstream club_80 { server club:80;}
upstream club_3000 { server club:3000;}

server {

listen 8090;
server_name _;
access_log /var/log/nginx/proxy.8090.access.log common;
error_log /var/log/nginx/proxy.8090.error.log;

source_charset utf-8;
charset utf-8;

recursive_error_pages on;

#upstream mapping
set $xport 80;
if ($http_host ~ ":(\d+)") { set $xport $1; }
set $upstr "club_${xport}";


error_page 417 = @cached;
error_page 418 = @nocached;

proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $connection_upgrade;

proxy_buffering off;

location / {

return 417;
}
location /socket.io {

return 418;
}

location ~ /(ru|en/)?index.html {

return 418;
}

#for index/socket.io
location @nocached {
proxy_read_timeout 86400;
proxy_cache off;
proxy_pass http://$upstr;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
add_header Cache-Control "no-cache,no-store,must-revalidate";
expires -1;
}

#for static
location @cached {

proxy_cache_methods GET;
proxy_cache_valid 200 5d;
proxy_cache clubcache;
proxy_pass http://$upstr;
proxy_set_header Host $host:$proxy_port;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

proxy_cache_bypass $cookie_nocache $arg_nocache$arg_comment;
proxy_cache_bypass $http_pragma $http_authorization;

proxy_ignore_headers X-Accel-Expires Expires Cache-Control Set-Cookie;

add_header Cache-Control "no-cache,no-store,must-revalidate";
expires -1;

}
}
================= END