Wordpress Site causing 504 Bad Gateway on 11.5.30

[JWT-Tech]

I am hosting about 10 WordPress sites on 11.5.30 Update #20 CentOS 5.10. I recently upgraded from Plesk 11.0 and have been having an issue with one of the WordPress sites. It randomly causes nginx to give a bad gateway 504 error that never goes away unless I reboot the server, the apache service or run httpdmng --reconfigure-all. Any of those fix the issue but after a few hours or days its back and the customer is telling me the site has been down for a few hours. I am trying to figure out if this is an issue with my server or an issue with this WordPress install that is causing the issue. Anyone got any ideas?

 

[IgorG]

Discussion of fixing 504 Bad Gateway error is here - http://forum.parallels.com/showthread.php?263798
I hope it will help.