YOU'VE BEEN BLOCKED!!!
Are you one of those benevolent souls with an MSN list exploding past capacity - filled mostly with "friends" who you do not speak with??? Perhaps, you never see them online...
Here is your remedy.
Be warned - it is not for the feint of heart.
After finding out who has callously deleted/blocked you ... you will find that it is less painful (even pleasurable) to shorten your contact list.