Hello, i'm implementing YARPP on a new blog site, the problem is that it looks like the widget only supports post, page and cross_relate for post_type leaving me with no support for the custom post type selected on the main settings.
My solution was to hack the widget class, and add this support, it would be nice to merge this to the plugin.
on file class-widget.php i added after line 27
else if ( in_array(get_post_type(), $yarpp->get_post_types()) ) $instance['post_type'] = array( get_post_type() );
This will give support for custom post types on the widget.