Header Error When Disabling Plugin

Hi, at the top of my blog I am getting this error (omit **) :

************

Warning: main(/home/teen/public_html/wp-includes/links-update-xml.php): failed to open stream: No such file or directory in /home/teen/public_html/wp-content/themes/polteen/header.php on line 6

Warning: main(): Failed opening ‘/home/teen/public_html/wp-includes/links-update-xml.php’ for inclusion (include_path=’.:/usr/lib/php:/usr/local/lib/php’) in /home/teen/public_html/wp-content/themes/polteen/header.php on line 6

************

Line 6 on header.php says (omit ***):

************

include_once(ABSPATH.WPINC.’/links-update-xml.php’);

************

I get this error when I disabled CG-Powerpack (http://www.chait.net/index.php?p=238) . I don’t understand why I get this error and how to fix it . Thanks