Dont know if this might help. from the Readme
Windows XP or Win2K plus MSN Messenger: Open your programs folder, open
Administraive Tools, open Services. Look for the service Universal Plug and Play,
and double click on it. Then select "Disable".
also, ensure that ICS (internet connection sharing) is disabled as well.
Might also wander over to:
www.blackviper.com and follow his "xp supertweak" advice, It might help.