never mind..found the piece of code in newtread.php
Code:
$scriptpath=ereg_replace("sessionhash=[a-z0-9]{32}&","",$scriptpath);
$scriptpath=ereg_replace("\\?sessionhash=[a-z0-9]{32}","",$scriptpath);
$scriptpath=ereg_replace("s=[a-z0-9]{32}&","",$scriptpath);
$scriptpath=ereg_replace("\\?s=[a-z0-9]{32}","",$scriptpath);
But still then..does it mather when users know other users sessionid?