Error 500 with 2 domain

[theprincy]

on two domains in the management admin error exit 500, the first (assolavori.it) uses wordpress, the second (revlab.net) uses AWBS.
The following portion of the log error of the two domains.

wordpress

Code:

- - [17/Sep/2009:13:57:19 +0200] "GET /wp-admin/edit.php?post_status=draft&s=&deleteit=Cancella&_wpnonce=cd774590f5&_wp_http_referer=%2Fwp-admin%2Fedit.php%3Fpost_status%3Ddraft&m=0&cat=0&delete%5B%5D=14489 HTTP/1.1" 500 468 "http://www.assolavori.it/wp-admin/edit.php?post_status=draft" "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.4; it; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3"

I also enabled in php.ini error_log but strangely is always 0 , can someone tell me how to solve?

ps :
could do the ping on this ip and tell me the result thanks

151.1.153.32
151.1.154.40
151.1.155.126
151.1.153.24