That's a question for webmaster of that server.
What is your home network setup?
I'm playing at game server which allow using few accounts at once but I can't use them at same place. If I'm near each other I got the msg like "Multi Client was detected. Automatic 5 sec exhaust." and I can use just 1 account cause other got exhaust. When I log from other PCs but with same network connection got same problem, only way is to log in to 2 pcs with other IPs BUT!
My friend can use all kind of multi clients even 10 at 1 PC and his home network setup is like "ADSL Street Connection > Filter > Phone/Modem > HUB > Router".
I'm so curious why he can use it and I can't, how does it work, any ideas? (I'm layman about Computer Networks)
Have a nice day,