I agree when blocked it should be handled in a way that Act! does not stop responding. Our QA folk will test / recreate that. Once they do I will post an update here. I will also take an action to update our KB for AV Firewall exceptions http://kb.act.com/app/answers/detail/a_id/25125/kw/firewall and then circulate around support.
I have a customer who has constant freezing. Have put the 5 min. mark on server and it is constant. Appears to be totally related. ACT!21 Pro, and new Del computers, no internet, has daily compress & re-index, confirmed port 1434 is open and removed McAfee on all workstations and server.