i am having a strange problem with schedule task

[dip1232001]

can anyone tell me how to stop a schedule task cause i have just added a schedule task and for that when ever it runs the usergroup id gets changed to banned id or some thing else can any one tell how to stop that schedule task?

i have added a php file in corn folder with these codes

<?php
/**
* VBulletin Torrent Tracker v3.0 for XBT v1.0 FINAL - VBXBT_Mod_2_VBTT 3.0 user/torrent/files transfer
* Coded by Toolmanwill
**/

error_reporting(E_ALL & ~E_NOTICE);

if (!is_object($vbulletin->db))
{
exit;
}


// ban users with low ratio

$vbulletin->db->query_write("UPDATE `user` SET `can_leech` = 0, `usergroupid` = 55 WHERE (`uploaded` / `downloaded`) < 0.25 AND `downloaded` > 1073741824 ");

// lift ban on users who improved ratio

$vbulletin->db->query_write("UPDATE `user` SET `can_leech` = 1, `usergroupid` = 55 WHERE (`uploaded` / `downloaded`) > 0.50 AND `downloaded` > 1073741824 ");


?>

i think the problem is in this code

// ban users with low ratio

$vbulletin->db->query_write("UPDATE `user` SET `can_leech` = 0, `usergroupid` = 55 WHERE (`uploaded` / `downloaded`) < 0.25 AND `downloaded` > 1073741824 ");

// lift ban on users who improved ratio

$vbulletin->db->query_write("UPDATE `user` SET `can_leech` = 1, `usergroupid` = 55 WHERE (`uploaded` / `downloaded`) > 0.50 AND `downloaded` > 1073741824 ");

can any one sort it out or rewrite it ......any kind of help i will be glad.. and one thing more if i wanna add more than one usergroup id then what should be the code look like...