I personally would suggest you to try installing MSN Messenger wuthout Plus! once, if you're still experiencing problems, that means the problems comes from your MSN Messenger, in that case I'd suggest you to downgrade to another MSN Messenger version, usually the 6.2 does the trick. You can find it here :
http://www.microsoft.com/downloads/details.aspx?F...FA1&displaylang=en
(Microsoft link, so you can trust it at a 100%)
Now if Msn Messenger 7 does work without Plus! then I think the best thing to do will be to contact Patchou, maybe with your OS and all other useful infos