Connecting to Applications on the 'Net

I've just been elected as the Flash Communication Server MX 'Expert' here at work. They've installed Flash Comm and we can browse to the sample applications. When we start one of these samples on the local machine, it connects and runs fine. When we try and hit them from outside our network, we can view the applications but they will not connect.

For clarifications sake, the Flash Comm MX installation came with a sample app called 'Panel Presentation' which has a chat and slide presentation that users login to, this isn't the only app we're having trouble with, just and example of what we mean by login.