I have a slightly different version of this problem. ZoneAlarm 2.1.25 will simply not allow me to host a server while it's running, though everything loads just fine. I've set it up to allow servers and connections as well, but no go. Shutting ZoneAlarm down fixes the problem.
Hard locks sound like as if the little window asking if you'd like Quake 3 Arena to be able to access the Internet comes up but you can't see it. Make sure Q3A has the always-allow selections set and give it a whirl?