problem with Cache-Control no-cache

[DaveTupe]

Hi,

I have a problem with Ubuntu + Plesk 11.5 + nginx
I need to cache html and jpg, but no way to do.
Always in Request Headers appears Cache-Control no-cache. Attachment file.
Config in Additional directives nginx:

gzip_proxied any;
expires 30d;
location ~* \.(js|css|png|jpg|jpeg|gif|ico)$ {
expires 30d;
add_header Pragma public;
add_header Cache-Control "public";
try_files $uri @fallback;
}

and checked the three checks in nginx config.

Help!

Regards