It doesn't crash for me, but I just created an empty tcpproxy.conf file (since it didn't start without it). Perhaps the crash depends on your config options. What's in your tcpproxy.conf? Can you tell us anything else about what triggers the crash?
Perhaps we should update the port to version 2.0.0-beta15. Normally we wouldn't update ports to unstable versions, but the old 1.1.9 version isn't even available on the developer's web site anymore, and 2.0.0-beta15 is listed there as the "current" version, and has been since September 2007.