Thanks Lester,
I read that just now…
1. I have wpsupercache and disabled it.
2. Not using .htpasswd
3. Not using https / ssl
It looks like some kind of js conflict but I get no errors in my firebug console. The only line in the All tab is this:
GET https://testyng.com/wp-admin/admin-ajax.php?actio...tratings_101841_nonce=1004565e55&_=1381933578038
… and this is the response (looks normal to me (one line per star the description after))
<img src="https://testyng.com/wp-content/plugins/wp-postratings/images/stars_crystal/rating_on.gif" alt="17 votes, average: 2.88 out of 5" title="17 votes, average: 2.88 out of 5" class="post-ratings-image" />
<img src="https://testyng.com/wp-content/plugins/wp-postratings/images/stars_crystal/rating_on.gif" alt="17 votes, average: 2.88 out of 5" title="17 votes, average: 2.88 out of 5" class="post-ratings-image" />
<img src="https://testyng.com/wp-content/plugins/wp-postratings/images/stars_crystal/rating_half.gif" alt="17 votes, average: 2.88 out of 5" title="17 votes, average: 2.88 out of 5" class="post-ratings-image" />
<img src="https://testyng.com/wp-content/plugins/wp-postratings/images/stars_crystal/rating_off.gif" alt="17 votes, average: 2.88 out of 5" title="17 votes, average: 2.88 out of 5" class="post-ratings-image" />
<img src="https://testyng.com/wp-content/plugins/wp-postratings/images/stars_crystal/rating_off.gif" alt="17 votes, average: 2.88 out of 5" title="17 votes, average: 2.88 out of 5" class="post-ratings-image" />
(<em><strong>17</strong> votes, average: <strong>2.88</strong> out of 5, <strong>rated</strong></em>)