[Contagious]

Well i'm currently hosting an online php based mmo..
Quite a lot of people from my school have started laying this game at school and have run into a problem.
When more then two users have logged in the tend to get another persons base.
I know this has to do with cookies and also how the school is networked (i think) it cannot be the fact that we use the same external ip's because i made a temp solution by making sub domains and seems to work as long as users don't use the same domain..

heres the cookie code:
[php]setcookie($game_config['COOKIE_NAME'], $cookie, $expiretime, "/", "", 0);[/php]any idea's on how to change this code to allow multi log ins from school using the same domain?

However i would like to find a solution. Also our school is networked using two domains teachers and students how the heck does it manager to share cookies with other computers on the network for these conflicts to happen?

[Contagious]

sory not too sure if this is the right section...