ibast

I had the same problem, but I got it working when I changed the div id:s to be unique.
The following code should work in your case, you can put it both in the loop (index.php) and on the individual page (single.php):

<div id="pd_rating_holder_810655_<?php echo( $post->ID ); ?>"></div>
<script type="text/javascript">
PDRTJS_settings_810655_<?php echo( $post->ID ); ?> = {
	"id" : "810655",
	"unique_id" : "wp-post-<?php echo( $post->ID ); ?>",
	"title" : "<?php echo( $post->post_title ); ?>",
	"permalink" : "<?php echo( get_permalink( $post->ID ) ); ?>",
        "item_id" :  "_<?php echo( $post->ID ); ?>"
};
</script>

And somewhere in the footer you can put

<script type="text/javascript" language="javascript" src="http://i.polldaddy.com/ratings/rating.js"></script>

Good luck!