File transfer within MSM Messenger

I have a bit of a problem.

Since upgrading to Windows Xp I have been unable to send any files accross to anyone (instant messaging) at all. It starts connectiong, and then, after about a minute, it say something like: "Unable to connect. Contact you ISP to enable file transfering"

This used to work OK on Win98 and nothing has changed with my ISP.

I'm guessing its some kind of firewall or protection.

The only protection I have is Noton Antvirus 2003.

Anyone else had this problem?

 

Is it a problem transmitting or does the issue recur while recieving as well, have you updated to the latest version of MSN messenger, are you trying to use Windows Messenger to connect to somebody else with MSN messenger, do you have the winxp firewall enabled, are you trying to connect through a router