My MSN has been rather unfair to me within the past few days and it has been blocking a certain contact in which I do not desire to block. I talked with this person and we tried to delete each other and re-add our contacts, but alas, to no avail. I seek wisdom. Who knows how to re-add previous contacts? I try to send invites, but it says it did not go through.
A similar thing already happened once with me before. After some tries, I deleted my friend and she deleted me. Then, I sent her an invitation. She said she didn't received it. So we made sure to check if she didn't have me and if I didn't have her. So, calmly I sent her an invitation, and... it worked! ...Weird. Is this what is happening to you?
I tried that, and it now looks like it is working... they had to send the invitation, not me for some reason. But I can't be sure till they are online and everything's working.