Yes, thanks for the plugins Lester Chan! I’ve found them very useful. I had the same issue as Marko, and it was fixed by adding a line to the wp-postratings php:
if (isset($_GET['rate']) && isset($_GET['pid'])){
…before these lines…
$rate = intval($_GET['rate']);
$post_id = intval($_GET['pid']);
(…and, of course, closing with }
at the end of the function.)
I guess you can use it if/when you update the plugin.