Wordpress page comments gets Fatal Error. HELPPP

Help..

My wordpress blog have problem with the comment. It strange because the error only in 1 page, http://www.justinbieberzone.com/about-justin-quick-facts/ the other pages has no problem. the page has more than 3000 user comments. This is the error:

this is the function.php file. Anyone can help? thanks

 

add this line to your wp-config.php

define('WP_MEMORY_LIMIT', '64M');