I'm still testing this as it was just thrown together in a few minutes to combat todays massive chatserver instability and the following massive spamming.
Use at your own risk etc, but it works for me.

Bot.php, function inc_buddy
Find
<?php
/*
Buddy logging on/off
*/
function inc_buddy($args)
{
$user = $this -> aoc -> get_uname($args[0]);

$mem = $this -> is_member($user);

$end = "";
if (!$mem)
{
?>

Change to:
<?php
/*
Buddy logging on/off
*/
function inc_buddy($args)
{
$user = $this -> aoc -> get_uname($args[0]);

$mem = $this -> is_member($user);

// Make sure we only cache members and guests to prevent any issues with !is and anything else that might do buddy actions on non members.
if ($mem)
{
// Buddy logging on
if ($args[1] == 1)
{
// Do we have a logon for a user already logged on?
if (isset($this -> glob["online"][$user]))
{
$this -> log("BUDDY", "ERROR", $user . " logged on despite of already being marked as logged on!!");
return;
}
else
{
// Enter the user into the online buddy list
$this -> glob["online"][$user] = $user;
}
}
else
{
// Do we have a logoff without a prior login?
if (!isset($this -> glob["online"][$user]))
{
$this -> log("BUDDY", "ERROR", $user . " logged off with no prior logon!!");
return;
}
else
{
unset($this -> glob["online"][$user]);
}
}
}

$end = "";
if (!$mem)
{
?>

Depending on what version of the bot you run, find the actual bot function near the top with all the variable declarations.
Make sure the following line appears:
$this -> glob = array();