This morning someone IM'd me, which I assume is a bot (they wanted me to go see their "new pictures"). Anyway, I right away hit "block" and closed the window.
Just now, the same user IM'd me with the same message, even though they're still blocked.
I had the same problem just 20 minutes ago. I am using Adium 1.3.6 and an ICQ spambot that IM'd me on the 2nd of August got through AGAIN now. It is 9 September 10:48 now (GMT)