Has anyone experienced anything like this?

Application: Windows Operating System
Direction: In
Protocol: UDP
Source IP: from many countries
Destination port: 18599

I am just wondering what is happening. I scanned my comp for malware and seems to be clean,
but there is still about 7000!!! connection attempts in my log July - October 2010, where about 5000 is just from October!

By the way, when I am exporting the log to an html file the port number changes from 18599 to 42824 ???.

Cheers :-TU