Shoutbox

okay, this is the second time this has happened to me and I'm totally confused why this happens, last time when this happened I had the newest msn 7.5 or something like that and all of a sudden I couldnt see any one online nor could anyone else see me online.  It wasnt my computer cause no matter where I logged on, the same thing happens.  Then I figured out that if I delete my friends from my contact list and readd them they would show up again and work fine.  But now the same thing happend again today and I dont wanna re-add everyone again... whatz wrong????