I've a problem when i try to send mass email in a forum. Nginx give me error 502, looking in the logs only give me this error.

"2011/08/31 16:40:54 [error] 25124#0: *3383 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: IP, server: domain.com, request: "POST /forum/index.php?action=admin;area=news;sa=mailingsend HTTP/1.1", upstream: "fastcgi://127.0.0.1:1000", host: "www.domain.com", referrer: "http://www.domain.com/forum/index.php?action=admin;area=news;sa=mailingcompose""

This happens 2 sec after script is executed.

I'm using nginx 1.04 and php-fpm 5.3.8