Updated server not sending/accepting multiple file uploads?

Question

I have two servers, server A and server B. A form on server A submits data to server B via XMLHttpRequest. Apache is set up to allow data to be sent from one server to the other, avoiding the cross-origin problem.

The form uploads files and is meant to be able to send multiple files at once. This worked fine with single and multiple file uploads with CentOS 5.3.

After using "yum list updates" and "yum update" to update the OS to CentOS 5.6, multiple files uploads stop working. The first file would be sent to server B, all other hidden input data was not sent, and the files information array $_FILES[] had a count() of zero. Single file uploads worked properly, $_FILES was created successfully, and other hidden input data was sent.

What could be causing this problem? Is it possible that some settings were changed during the upgrade? (The server was rebooted after the installation.)

Thanks in advance! tundoopani

EDIT: I don't think this is caused by the centos upgrade. The problem now occurs on 5.3 and 5.6. :( It seems the data is sent in pieces causing multiple requests?