Trojan?
Nah, I think it's a bug. You could see if this helps:
If you're running WLM 8.0.812, please download 8.1.178 from http://get.live.com/messenger/overview
If you're already running WLM 8.1.178 or greater, try disabling all your scripts, if you got any, and if the problem still is there, uninstall MP!L.
If the problem is gone then you know it's caused by MP!L, and should report the bug to Patchou.
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