Messenger problems.

[Albion]

I use Messenger a lot and have no problems with it but a friend of mine is having huge problems with it and we can't seem to find a solution.

He can log on OK and send emoticons and his webcam works fine but if he types a message and tries to send it he gets logged out.

He's useing Windows XP and the latest version of Messenger.
I've got him to look at firewall settings, anti-virus software etc... and hunted around on the net but found no solution.

Can anyone here help please?