validation error - Google +1 button

I'm trying to 开发者_开发知识库remove the counter from the google +1 button, but am getting this result: there is no attribute "g:plusone:count"

Here is the code:

<div id="add" class="addthis_toolbox addthis_default_style addthis_32x32_style">
<a class="addthis_button" href="http://www.addthis.com/bookmark.php">
<img src="/images/add.jpg" width="32" height="32" alt="Share" /></a>
<a class="addthis_button_preferred_1"></a>
<a class="addthis_button_preferred_2"></a>
<a class="addthis_button_preferred_3"></a>
<a class="addthis_button_google_plusone" g:plusone:count="false"></a>
</div>
<script type="text/javascript" src="http://s7.addthis.com/js/250/addthis_widget.js#pubid=ra-4d766a8d31dffc91"></script>
<script type="text/javascript">
var addthis_config = {
     services_exclude: 'print'
}
</script>

Anyone know how I can keep the counter off and still validate in xhtml strict?