Index: wp-includes/media.php
===================================================================
--- wp-includes/media.php	(revision 7209)
+++ wp-includes/media.php	(working copy)
@@ -50,6 +50,9 @@
 // returns an array($url, $width, $height)
 function image_downsize($id, $size = 'medium') {
 
+	if ( !wp_attachment_is_image($id) )
+		return false;
+
 	$img_url = wp_get_attachment_url($id);
 	$meta = wp_get_attachment_metadata($id);
 	$width = $height = 0;
@@ -71,8 +74,6 @@
 			$width = $info[0];
 			$height = $info[1];
 		}
-		else
-			return false;
 	}
 	elseif ( isset($meta['width'], $meta['height']) ) {
 		// any other type: use the real image and constrain it
@@ -261,16 +262,14 @@
 function wp_get_attachment_image_src($attachment_id, $size='thumbnail') {
 	
 	// get a thumbnail or intermediate image if there is one
-	$image = image_downsize($attachment_id, $size);
-	if ( $image ) {
-		list ( $src, $width, $height ) = $image;
-	}
-	elseif ( $src = wp_mime_type_icon($attachment_id) ) {
-		$icon_dir = apply_filters( 'icon_dir', get_template_directory() . '/images' );
+	if ( $image = image_downsize($attachment_id, $size) )
+		return $image;
+
+	if ( $src = wp_mime_type_icon($attachment_id) ) {
+		$icon_dir = apply_filters( 'icon_dir', ABSPATH . WPINC . '/images/crystal' );
 		$src_file = $icon_dir . '/' . basename($src);
 		@list($width, $height) = getimagesize($src_file);
 	}
-	
 	if ( $src && $width && $height )
 		return array( $src, $width, $height );
 	return false;
Index: wp-admin/edit-attachment-rows.php
===================================================================
--- wp-admin/edit-attachment-rows.php	(revision 7209)
+++ wp-admin/edit-attachment-rows.php	(working copy)
@@ -39,14 +39,14 @@
 
 	case 'icon':
 		?>
-		<td class="media-icon"><?php echo the_attachment_link($post->ID, false, array(48,48)); ?></td>
+		<td class="media-icon"><?php echo get_the_attachment_link($post->ID, 'thumbnail', array(48,48)); ?></td>
 		<?php
 		// TODO
 		break;
 
 	case 'media':
 		?>
-		<td><strong><a href="# TODO: upload.php?action=edit&amp;post=<?php the_ID(); ?>"><?php the_title(); ?></a></strong><br />
+		<td><strong><!-- TODO <a href="upload.php?action=edit&amp;post=<?php the_ID(); ?>"> --><?php the_title(); ?><!-- </a> --></strong><br />
 		<?php echo strtoupper(preg_replace('/^.*?\.(\w+)$/', '$1', get_attached_file($post->ID))); ?>
 		<?php do_action('manage_media_media_column', $post->ID); ?>
 		</td>