[Dragon]

In order to stop people from signing up for another account with the same IP, why not just add a piece of code like this to the signup page...

$ip = $_SERVER['REMOTE_ADDR'];
$query = mysql_query("SELECT * FROM `User` WHERE Signup IP='$ip'");
$rows = mysql_num_rows($query);
if($rows<0){
normal code...
}else{
echo"I'm sorry, but the IP ($ip) has already been used.";
}

Then, once that the people that haven't signed up have signed up for an account, then just use a query to insert their IP in to the table, so that if they try to signup again, they won't be able to.

It just doesn't make sense to allow people to signup again on the same IP, when you could just simply stop them from doing so. That would probably save Zenith some time checking the database for multiple IP addresses and while doing this, also allowing Zenith to use that saved time for more on the development on this game.