Index: wp-admin/custom-background.php
===================================================================
--- wp-admin/custom-background.php	(revision 20941)
+++ wp-admin/custom-background.php	(working copy)
@@ -234,7 +234,8 @@
 </tr>
 <?php endif; ?>
 
-<?php if ( get_theme_support( 'custom-background', 'default-image' ) ) : ?>
+<?php $default = get_theme_support( 'custom-background', 'default-image' ); ?>
+<?php if ( $default && $default != get_background_image() ) : ?>
 <tr valign="top">
 <th scope="row"><?php _e('Restore Original Image'); ?></th>
 <td>