I've just updated the plugin to version 2.0 and it's not working properly.
At footer I had a widget with the most rated, and now it gives me an error:
Fatal error: Call to undefined method PostRatings::options() in /home/xxxxxxxxxxxx/public_html/wp-content/plugins/post-ratings/widget.php on line 382
Also, it has broken the WP widgets page! Had to disable plugin to make the widgets page work properly again.