You could try to find out by installing zonealarm, its a software based firewall, when you first attempt to connect that program to the net it will pop up a box asking if you want to allow such and such a program to connect, it should give the port # of the outbound connection attempt.
you can get it free @
http://www.zonealarm.com
Make sure to uninstall it once you've got the ports or your gonna have another headache with the software based firewall
