the Everquest Emulator people have similar problems with their loginserver, it is a vulnerability in the netcode as a result of the reverse engineering process one of the former devs from that project now one of the devs of EQ2emu
http://eq2emulator.net has fixed the problem with their login system his sn is image you can get a hold of him here
http://eqemu.devnoob.com Im not sure how he did it but he implimentd some major security upgrades to the login server and since all soe games use the same netcode maybe you can talk to him hes a pretty good guy and will probably tell you how to shore up the LS Security. Hes prety much an expert on the SOE netcode encryption and protocols.
as for DoS attacking you cant get more lame then that. Im not a huge fan obviously but seriously if your reading this please know that you are a fail of epic scale.
BTW programmers are hackers crackers are the script kiddies that do DoS Attacks and crap like that please dont confuse the two