OS 10.4 - Open, Unassigned Port

After running a full port scan on my G5 using Network Utility, it turns out that port 47807 is open.

My question is, why?

From previous incidents involving this same port in association with heavy spam/Windows Messenger traffic to P: 1026 (CAP—Calendar Access Protocol) and p: 1027 I'm now beginning to suspect a pattern involving Intego.

Since my G5 is running the Intego NetBarrier firewall vX4, and since I only notice port 47807 being open after installing NetBarrier. . .

Well, it still remains a mystery. But I've contacted Intego, who in their usual hauty fashion have refused to reply.

47807 is apparently [for one] a factory network port, used by Intego in the development of iCalendar. What else it is remains a big question mark. . . but if anyone can offer me a leg up I will be grateful for at least one full hour, haha.