Anyone familiar with XML-RPC for PHP?

Hi, hope someone can help with this issue that I’m facing.

To cut the long story short, I am trying to setup a WordPress plugin to allow users on the websites that I develop to contact me from within their wp-admin panel directly, and send tickets to my support website remotely. I checked the plugin source and noticed that it uses the [URL=“http://sourceforge.net/projects/phpxmlrpc/”]XML-RPC for PHP library. Anyone at all familiar with it, the “Server” script that is required by the plugin to connect to does not work on all servers, so I assume it’s some server restriction that prevents XML-RPC to work properly, and a “Connection failed” error message is displayed on the client website. I tested on 2 VPS servers, it works on one of them, and fails on the other.

Is there something about XML-RPC to consider when setting up the server to run it on in order to grant connection to the remote server and allow remote ticket posting with it?