Inconsistent behavior

On some pages (http://digitalestedenagenda.nl/dsa-publieke-veranderaar/) I have working code, on some (non-compressed) pages (http://digitalestedenagenda.nl/open-data-afval-waardevol/) all sorts of AddThis code is inserted, apart from the widget.js, so no code is executed when a user clicks. What might be causing this? I’m using the same code on all posts

<div class="addthis"><span>deel dit</span>
						<?php do_action(
				'addthis_widget',
				get_permalink(),
				get_the_title(),
				array(
					'size' => '16',
					'services'=> 'linkedin, twitter, facebook, email',
					'preferred' => '0',
					'more' => false
					) ); ?></div>

http://wordpress.org/plugins/addthis/