trying to enter in Add this code

I am trying to add this code in the editor on my webpage...I save it and it looses half of it
<!-- 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_google_plusone" g:plusone:size="medium"></a>
<a class="addthis_counter addthis_pill_style"></a>
</div>
<script type="text/javascript" src="http://s7.addthis.com/js/250/addthis_widget.js#pubid=xa-4e7e95e33aa08791"></script>
<!-- AddThis Button END -->

After i save it looks like this

<!-- AddThis Button BEGIN -->
<div class="addthis_toolbox addthis_default_style ">&#160;</div>
<script type="text/javascript" src="http://s7.addthis.com/js/250/addthis_widget.js#pubid=xa-4e7e95e33aa08791"></script> <!-- AddThis Button END -->

I have 2.6.4 and i need help..thanks!