Creation of an unread messages block.

Hi there,

I've installed privatemsg 6.x-2.x-dev and am trying to show a block of
unread messages (titles and sender maybe) constantly up the top of every
page.

I followed the instructions at http://drupal.org/node/624528, created the
module and the block changing 'inbox' to 'unread' however am getting the
following error.

Fatal error: Call to undefined function _privatemsg_list_headers() in
C:\wamp\www\mysite\sites\all\modules\privatemsg\privatemsg.module on line
884

I'm guessing cause it's not an actual page this error is being thrown??
Noticed the function was found in privatemsg.pages.inc

I apologise if this is the wrong spot to place this message. Thanks for your time.