Just to clarify (for you and for anyone else who stumbles across this thread!)..
ping is a useful utility because, unless firewalls and stuff are actively stopping it, ANY device on an IP network should respond. The problem with using a web browser etc is that it relies on a much higher-level application (a web server) running on the device. A lot of kit doersn't have such an application and many that do have them running on non-standard ports, for various reasons. Ping is a lot quicker too!
Regarding the reboot thing. LinuxMCE is a complex system that sits on top of a Linux Operating System (the Kubuntu distribution). Part of LinuxMCE is a piece of software that passes event messages between the various subsystems. This is known as the DCE Router and, as I understand it, that is what is reloaded by the "reload router". The IP address is handled by a much lower part of the system, far closer to the OS. Now, there are ways of getting that part to re-configure without a reboot and I don't know for sure if MCE does this itself, but the surest way of making it re-configure is a reboot, then EVERYTHING gets reloaded! (Maybe I have been playing with Windoze too much, hell you walk past a Windoze box and it needs a reboot
) If you system doesn't survive a reboot, you have problems anyway, since there will be times that you need to bring the server down (like to upgrade hardware) so you need to be sure that you can do this ok. Simply editing the config files does not necessarily cause the system to use the new config.
Of course, my suggestions may not help, in which case you are probably no worse off......