EDIT: **UPDATE (June 10th 2012)**

I can't figure out what's wrong with my codes.
When I want to share one of my blog posts and use either the Facebook share button or copy the link of the blog post directly into Facebook all that pops up is the URL itself, not the meta info such as description or featured image!
I filled out the meta data for each and every post and I also added Open Graph to my code.


I used this code in my function.php:

    //Adding the Open Graph in the Language Attributes
    function add_opengraph_doctype( $output ) {
    		return $output . ' xmlns:og="http://opengraphprotocol.org/schema/" xmlns:fb="http://www.facebook.com/2008/fbml"';
    	}
    add_filter('language_attributes', 'add_opengraph_doctype');
    
    //Lets add Open Graph Meta Info
    
    function insert_fb_in_head() {
    	global $post;
    	if ( !is_singular()) //if it is not a post or a page
    		return;
            echo '<meta property="fb:admins" content="YOUR USER ID"/>';
            echo '<meta property="og:title" content="' . get_the_title() . '"/>';
            echo '<meta property="og:type" content="article"/>';
            echo '<meta property="og:url" content="' . get_permalink() . '"/>';
            echo '<meta property="og:site_name" content="Your Site NAME Goes HERE"/>';
    	if(!has_post_thumbnail( $post->ID )) { //the post does not have featured image, use a default image
    		$default_image="http://example.com/image.jpg"; //replace this with a default image on your server or an image in your media library
    		echo '<meta property="og:image" content="' . $default_image . '"/>';
    	}
    	else{
    		$thumbnail_src = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'medium' );
    		echo '<meta property="og:image" content="' . esc_attr( $thumbnail_src[0] ) . '"/>';
    	}
    	echo "\n";
    }
    add_action( 'wp_head', 'insert_fb_in_head', 5 );


Yet, when I try to share my blog post links on Facebook, neither the meta description nor a thumbnail would show up for the majority of my blog posts. It's like something is blocking the information. I've run out of ideas. I really hope you guys can help me figure out what's wrong!
(obvioulsy I replaced the fillers above with my own data!)

I also used the Facebook Debugger and all it tells me is:

> Can't Download:	Could not retrieve data from URL.

An example for a blog post that can't be shared properly: http://zoomingjapan.com/favorite-photos/yumebutai/

There are very few blog posts that work with Facebook.
If I copy the URL of one of those into the Debugger I still get an error message, though:

> Object Invalid Value:	Object at URL
> 'http://zoomingjapan.com/travel/mount-koya-travel-report/' of type
> 'article' is invalid because the given value '377035309011137' for
> property 'fb:admins' could not be parsed as type 'fbid'.

The URL above is that of a blog post that could be shared properly, but yet gets an error message.

I can't figure out what the difference is.
Please help me out here!
Thanks a lot in advance for any advice you can give me.