Unique? I don't think so, have you checked the basic stuff? Like portforwarding and making sure any other firewall is not blocking port 8602 TCP and UDP OR the XBC program?
If that doesn't help, install/check the checkbox for "Use WinPCap Library" under Tools>Options>General Options in XBC.
Also, if you are using Windows Vista OR Windows 7 you will have to install a different version of WinPCap to make it work, or you could just run XBC in compatibility mode with Windows XP SP2 & SP3.
Just read through (
this and
this) thread.