Gateway timeout error from proxy server I was recently developed a drupal site for a client who lives in HongKong. The site worked perfectly (is still functional when I access it)
But after deploying it for demo, the client compalained that the site wasnt working and constantly getting a 504 Gateway timeout error.
Apparently the client was on a proxy server (and I'm guessing the problem is due to that factor).
Does anyone know of such problem?? And, of course, the way to fix it?

P.S.

The site is built on Drupal 7.14

This is a screenshot that the client sent me

(The server, while acting as a gateway or a proxy, did not receive a time response from the upstream server it accessed in attempting to complete the request)


Update::

On further investigating with the client, He told me that


The site first worked fine until he logged in as admin and added content.
The timeout error showed when submitting the content form.
After the error, no other page of the site would open.
The site did function when he tried after waiting for a while (he did not account the time he waited)


UPDATE ::

ON checking the error log on the server, I found a bunch of "Page not found errors". But the weird thing is it was looking for a 406 page (for unacceptable header). Any idea why??

[Mon Sep 30 16:45:30 2013] [error] [client 110.44.113.254] File does not exist: /home/ekmauka/public_html/404.shtml
[Mon Sep 30 16:45:30 2013] [error] [client 110.44.113.254] File does not exist: /home/ekmauka/public_html/favicon.ico
[Mon Sep 30 16:45:29 2013] [error] [client 110.44.113.254] File does not exist: /home/ekmauka/public_html/404.shtml
[Mon Sep 30 16:45:29 2013] [error] [client 110.44.113.254] File does not exist: /home/ekmauka/public_html/demo
[Mon Sep 30 16:31:17 2013] [error] [client 110.44.113.254] File does not exist: /home/ekmauka/public_html/406.shtml, referer: http://ekmauka.com/ekmauka/
[Mon Sep 30 16:20:40 2013] [error] [client 110.44.113.254] File does not exist: /home/ekmauka/public_html/406.shtml, referer: http://ekmauka.com/ekmauka/content/mongolian-heart-live-hongkong-2012
[Mon Sep 30 16:20:13 2013] [error] [client 110.44.113.254] File does not exist: /home/ekmauka/public_html/406.shtml, referer: http://ekmauka.com/ekmauka/node/22/edit
Maybe the PHP memory_limit, after submit content it take a lot of memory for PHP and it die.

You can request they increase memory_limit to check. But to get more information correct, can they give the error.log of webserver and error_log of PHP for easy know what happend.