I saw this fix while searching for something on unrealadmin.org and remembered this thread.

This is for the people who have the server browser problem in UT99 on Vista (or Win7 if the problem exists on there).

http://www.unrealadmin.org/forums/showthread.php?t=28914

[quote:3997606a00]This is a small fix for the UT Server browser on windows vista.
Because of a problem with the UdpLink.BindPort() function the browser
will either be very slow or not work at all. Unzip these files to your
system folder to fix the problem. The mod will load automatically.

-- AnthraX[/quote:3997606a00]