I don't think the problem is with some kind of protection, this is a known problem with Private RO servers, take a look at this thread on the WineHQ
http://bugs.winehq.org/show_bug.cgi?id=3962
At first people thought that the server address wasn't read correctly because of the different korean encoding of the GRF file, but now the problem seems different: in the debug you can see that the server address is resolved correctly but then is stored and "lost" in the memory...
On Wine in Linux the solution is very simple, you have to just use an iptables command like that:
iptables -t nat -A OUTPUT -d (bad ip here) -j DNAT --to (true ip here)
where the bad ip in my case is: 97.109.101.46
and the good ip of EUphRO (ping game.euphrogame.com) is: 69.65.40.153
to redirect all the traffic from the bad to the good address.
Unfortunately I don't know MAC OS very well so I don't know how to "translate" that command in "ipfw" that is, as far as I know, the firewall program in MAC.
If anyone can try it on ipfw (or tell me the command) it would be very helpful.
Thanks