Shoutbox

As long as they can talk to you and you can talk to them, it's kinda irrelevant.

As stated above the "Has you?" information is not necessarily correct, the only real way is if they can start a conversation with you.

They shouldn't just disappear from your allow list without you blocking them or anything......but as you had them blocked it's possible if you signed onto another computer it would still see them as blocked and remove them from the allow list or anything like that

Edit: is it perhaps that they're showing up as their display name instead of e-mail address, or vice-versa.  I've noticed in my lists that it can be random as to how a person appears in the lists.