Many web proxies (e.g. BlueCoat) behave like Man-in-the-Middle (MitM) attackers--modifying the traffic between you and the server you're connecting to. Because Gate One has strict security controls to prevent MitM attacks, such proxies can result in connection problems (e.g. a "black screen" or being asked to re-authenticate). Often these issues can be worked around by connecting directly to the Gate One server--as opposed to connecting from a different web page (like the ESC key demo).
Another way to work around these issues is to use SSL (HTTPS) but even with that some web proxies just plain don't work. For these situations we recommend setting up a Gate One server inside your network to try it out on your own. Feel free to contact us if you need assistance or would like to schedule a formal walk-through demonstration.