The Problem with windows Messenger is not with your Anti Virus or McCaffe or Norton, it is a malware bot that attatches itself to the MSIN.EXE file that runs Email and Messenger, Your Anti Virus and Firewall programs allow it to run as you have Messenger allowed privillages to run in your Firewall program, This Virus on Msn Messenger, actually overwites the Messenger lib files and gives the illusion that messenger works fine, which it does, but the original file that came with MSN Messenger has been deleted and replaced with this Virus One.
TAKE NOTE!! GO TOO LIVE MAIL WEB PAGE and change your password there, DO NOT USE MSN MESSENGER PROGRAM TO DO THIS,
This will illiminate The problem
Or if you Wish to be sure and go further...
Uninstall The Version You have of MSN
Then after that...search MSN and search Messenger on your computer, this bugger of a file will leave remnances in folders and pieces left over after install...so find anything to do with MSN and MESSENGER and delete the lot off your computer, delete the messenger cache Then once done, turn off SYSTEM RECOVERY...and Reboot
Then Turn On System recovery and Install a new MSN Messenger. then TAKE NOTE!! GO TOO LIVE MAIL WEB PAGE and change your password there, DO NOT USE MSN MESSENGER PROGRAM TO DO THIS,
Then when complete, open your new MSN Program, Dont Tick (AUTO SIGN ON) enter your password manually for about 10 times when you log in.....THIs Stops it all.
Microsoft are aware of this malicious Spam Bot attaching itself to promote porn sire advertising and have created a Clean tool and malware remover specifically designed to hunt down and remove known component names this Virus uses, it is called "Clean Virus MSN"