This program seem to be using iptables to manage network connections and traffic.
iptables is not a service. It shows up as a service in a service list for easy access and management. All it does when you stop it is delete all iptable rules and all it does when you start it up is reading iptables rules from a text file and apply them. It is not something that constantly run waiting to service a client like a true service/daemon.
i think you will be ok if you stop iptables "service" and set it to not start at boot time and then restart your computer while setting firestarter to start at boot time. At the end of the day, this firestarter is doing nothing but adding its own iptable rules.
i should try to write short posts. my long posts almost always guarantee that somebody else will post before me