Index: modules/aggregator/aggregator.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/aggregator/aggregator.module,v
retrieving revision 1.389
diff -u -r1.389 aggregator.module
--- modules/aggregator/aggregator.module	16 Aug 2008 14:48:17 -0000	1.389
+++ modules/aggregator/aggregator.module	23 Aug 2008 09:01:49 -0000
@@ -631,7 +631,7 @@
           $image = '<a href="' . check_url($image['LINK']) . '" class="feed-image"><img src="' . check_url($image['URL']) . '" alt="' . check_plain($image['TITLE']) . '" /></a>';
         }
         else {
-          $image = NULL;
+          $image = '';
         }
 
         $etag = empty($result->headers['ETag']) ? '' : $result->headers['ETag'];