One of my clients just installed a firewall and since installing it they've been having issues uploading largish files (tested with files over 2MB ~ 200MB) to our server. The server is running Ubuntu 10.04 and Apache 2.2.14 and another test server is running Ubuntu 10.04 with Apache 2.2.16. From the clients location large uploads produce a "request failed: error reading the headers" in the error.log.
The form that's posting the large files is posting to a PHP script.
The issue started with the firewall and when the firewall is removed from the equation everything is fine, unfortunately this isn't an option.
I realize the issue might be completely related to the firewall but they're not having issues posting the same files to other sites and I'm hoping there might be something I might be able to change on my end or something more I can look for that could help alleviate this issue.
If it's happening when their firewall is in place, and not happening when they remove it, then the issue is almost certainly on their end. So don't make any changes to your configuration at this point.
Suggest they look into: