I think i found what's wrong? But it's still weird..
Well, as you suggested, i turned i turned the notifications off. Just few minutes ago i heard it. I checked the msn event log file, and it turned out someone has changed thier nick/came online but they are blocked. The thing is, it's turned off. How could it make any sounds?
Unless it's the "Everytime one of your contacts signs in or out..", which i think it is.
Bummer..i should have looked through it all more.
I'm sorry, it's just that i am not quite familiar with the new Msn
..not that it has anything to do with Plus!
Thanks a lot though