Sent data:
"><script>alert(document.cookie);</script>
That is a possibility to take over an user account from http://skapiec.pl, when the logged user would click at specially crafted URL.
Timeline:
2007.05.22 bug discovered
2007.05.22 bug sent via mail from http://www.skapiec.pl/site/doc/1 [uwagi]
2007.05.23 fixed and fast answer via e-mail