ZA Free -- Windows 7 64-bit

I have a server program I run, and my friends run the client. Since upgrading the server machine to Windows 7, and the latest ZA for Windows 7, the server no longer gets the requests from the client. They are blocked by the rule ExtBlockAll2, according to the log. Sometimes my server will establish the TCP connection after a reboot, but then subsequent connections are blocked. I'm not sure whether to consider the successful first connection to be a bug in the bug that blocks the remaining connections, or just how I should think about it.

I wrote both client and server programs, and they work fine in the trusted zone, but not the internet zone, in spite of allowing access when I got the popups.

So the internet zone security is high, and trusted is medium. But that's how it was on XP, and it worked there.

Is there a solution?