CKFinder 2.4 gives Unknown Source error when testing over network

Hi guys. I'm new to CKFinder and have installed the PHP version of CKFinder. (unlicenced - testing)

I've followed the getting started guide and tested the standalone sample page. All works as expected except the thumbnails don't display (Not my main issue, but could be later).

My main issue is that the moment I test the same standalone sample page over a network (not on the local server) I get "It was not possible to properly load the XML response from the web server."

I've left the config files as default as possible. I've attached the error, as far as I was able to get to (could not figure out how to enable proper debugging). The attached file is the html source of the System Error dialogbox that comes up. Don't know php from a bar of soap, so bare with me please.

Any help would be greatly appreciated. This is a fantastic tool and I will definitely recommend this tool to my company once I can get all features to work 100%.

Thanks again for the help.