AddThis

Tweet button generates "undefined" as URL Title

The Twitter button generate "Undefined" as Title. URL is fine.

Code used:
<!-- AddThis Button BEGIN -->
<div class="addthis_toolbox addthis_default_style ">
<a class="addthis_button_facebook_like" fb:like:layout="button_count"></a>
<a class="addthis_button_tweet"></a>
<a class="addthis_button_pinterest_pinit"></a>
<a class="addthis_counter addthis_pill_style"></a>
</div>
<script type="text/javascript">var addthis_config = {"data_track_addressbar":true};</script>
<script type="text/javascript" src="http://s7.addthis.com/js/250/addthis_widget.js#pubid=liewcf"></script>
<!-- AddThis Button END -->

Example URL: http://www.liewcf.com/epson-e200-wristwatch-pulse-monitor-8589/#.UCU6WRoe7JV

Screenshot of error: https://skitch.com/e-liewcf/em6p9/share-a-link-on-twitter

Please help. Thank you.