Zonealarm blocking all UDP servers

I'm having trouble getting Zonealarm to allow traffic to applications
that serve on UDP. In particular I am noticing this on two games:
Starsiege: Tribes and Quake II, and noticing it in a P2P program
called eMule (using a network called Kademlia).

The applications are set to be allowed to act as servers, and they
were working before I installed the firewall. I am also able to get
traffic to servers on TCP, including my web server and my FTP server.
The firewall is only causing problems to UDP.

The setting "Allow uncommon protocols at high security" in the
firewall tab under "Advanced" did nothing. I'm not sure what that
does, but would like to know.