proxy_pass http://backend;
proxy_redirect http://www.site.ru/ /;

А бекэнд и www.site.ru разные хосты?

--
Respectfully,
Stanislav Putrya
System administrator
Fotostrana.Ru.
ICQ IM: 328585847
Jabber-GoogleTalk: root.vagner
mob. phone: +79525600664
email: putrya@playform.com
email: vagner@bsdway.ru
email: root.vagner@gmail.com

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