block does not work

[icecreamsoda]

I have blocked several colleagues at work. Recently though I have noticed
that whenever I log in, a particular colleague whom I did block, is not
blocked on my list when I log in. After I log in to Windows Messenger, I am
able to block this person. But when I log out, and log back in, this person
is unblocked again. And I didn't unblock this person when I logged out not
even accidentally . I don't seem to have this problem with any other folks
that I've blocked on my list. Would appreciate any insight or feedback.
Thanks.