Occasionally, I'll get a steep spike in load due to apache process, and had one this morning. Restarting Apache often gets rid of the problem. Pulling up the apache error_log for the time period, there's only one item that stands out: Code: [Mon Jul 24 07:50:10 2006] [error] [client 188.8.131.52] File does not exist: /home/myclient/public_html/404.shtml *** glibc detected *** double free or corruption (!prev): 0x0a3b4950 *** exim: SIGTERM received - message abandoned [Mon Jul 24 07:51:22 2006] [warn] pid file /usr/local/apache/logs/httpd.pid overwritten -- Unclean shutdown of previous Apache run? [Mon Jul 24 07:51:22 2006] [notice] Apache/1.3.36 (Unix) mod_auth_passthrough/1.8 mod_log_bytes/1.2 mod_bwlimited/1.4 PHP/4.4.2 FrontPage/184.108.40.20635.SR1.2 mod_ssl/2.8.27 OpenSSL/0.9.7a configured -- resuming normal operations [Mon Jul 24 07:51:22 2006] [notice] suEXEC mechanism enabled (wrapper: /usr/local/apache/bin/suexec) [Mon Jul 24 07:51:22 2006] [notice] Accept mutex: sysvsem (Default: sysvsem) I did restart apache either during the time of this error log or shortly thereafter. In previous threads, users were requested to post the results of php -v and mine is: Code: PHP 4.4.2 (cli) (built: May 25 2006 03:08:50) Copyright (c) 1997-2006 The PHP Group Zend Engine v1.3.0, Copyright (c) 1998-2004 Zend Technologies The "myclient" website the initial error was tacked onto: After looking at the access logs, the only thing to note is that msnbot was cruising that site at the time. That website/user is particularly unremarkable and the webmaster is one of my partners. Separately, I did have a PHP based mailer program working on another website at the time (PHPList) Any ideas on this? Is this a Zend thing, or httpd.conf thing?