in cleanup.php which you can find in the include folder
comment out or delete
Code:
$dt = sqlesc(get_date_time(gmtime() - $torrent_ttl));
$res = mysql_query("SELECT id, name FROM torrents WHERE added < $dt AND manual_delete = 'no' AND seeders=0 AND leechers=0");
while ($arr = mysql_fetch_assoc($res))
{
@unlink("$torrent_dir/$arr[id].torrent");
mysql_query("DELETE FROM torrents WHERE id=$arr[id]");
mysql_query("DELETE FROM peers WHERE torrent=$arr[id]");
mysql_query("DELETE FROM comments WHERE torrent=$arr[id]");
mysql_query("DELETE FROM files WHERE torrent=$arr[id]");
write_log("Torrent $arr[id] ($arr[name]) was deleted by system, older than TTL");
}