[eluser]alexsancho[/eluser]
You're right wakeextreme, $_POST is repopulated after validation,
extract from validation library
Code:
/**
* XSS Clean
*
* @access public
* @param string
* @return string
*/
function xss_clean($str)
{
$_POST[$this->_current_field] = $this->CI->input->xss_clean($str);
}