Index: wp-admin/upload.php
===================================================================
--- wp-admin/upload.php	(revision 17378)
+++ wp-admin/upload.php	(working copy)
@@ -111,6 +111,9 @@
 			break;
 		case 'delete':
 			foreach ( (array) $post_ids as $post_id_del ) {
+				if( ! get_post( $post_id_del ) )
+					continue;
+				
 				if ( !current_user_can( 'delete_post', $post_id_del ) )
 					wp_die( __( 'You are not allowed to delete this post.' ) );