possible to use URI library in pre_controller hook?

[eluser]the real rlee[/eluser]
Hi, this may be a silly question but is it possible to use the URI library in a pre_controller hook? I'm getting errors telling me the object doesnt exist, but the User Docs indicate that the URI class is pre-loaded with CI and pre_controller hooks are after everything CI is loaded... Am I missing something here? Appreciate any help

Code:

$hook['pre_controller'] = array('class'=>'History', 'function'=>'update', 'filename'=>'History.php', 'filepath'=>'hooks', 'params'=>array());

And my hook:

Code:

class History {

var $CI;

function History(){
  $this->CI =& get_instance();
}

function update(){
  die($this->CI->uri->uri_string());
  $this->CI->session->set_userdata(array('location'=>$this->CI->uri->uri_string()));
}

}