Start up port

I don't know what it is called and why it does it exactly but when Limewire is first starting and you either get it to start or you get the firewall message, Limewire tries to send something outbound TCP through port xxxx. This isn't the same port as the listening port settings. If the port is blocked the program doesn't start and the next time you try to use limewire, it chooses a different port.

What I want to know is, is there a way to force Limewire to use only the port I tell it to for this start up check thing it does? Again, this doesn't seem to be related to the listening port settings of the firewall configuration in limewire.