php-fpm for php5.4-Collection of common programming errors

Nginx works in conjunction with php-fpm, php5.4.

When submitting a form with the Content-Type multipart / form-data obtained by this error:

2012/09/21 18:54:47 [error] 31051#0: *9 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: x.x.x.x, server: x.x.x.x, request: “POST /admin/news/edit.php?news_id=9032&action=edit HTTP/1.1”, upstream: “fastcgi://127.0.0.1:9900”, host: “x.x.x.x”, referrer: “http://x.x.x.x/admin/news/edit.php?news_id=9032&action=edit”

It is written in the log Nginx. What could be the problem?

php-fpm wrote in his log that:

[21-Sep-2012 19:19:34] WARNING: [pool www] child 1496 said into stderr: “php-fpm: pool www: symbol lookup error: /usr/local/php5.4/lib/php/extensions/no-debug-non-zts-20100525/suhosin.so: undefined symbol: php_mb_encoding_translation” [21-Sep-2012 19:19:34] WARNING: [pool www] child 1496 exited with code 127 after 21.748877 seconds from start

[21-Sep-2012 19:19:34] NOTICE: [pool www] child 1507 started