Index: Zend/Service/Amazon/S3.php
===================================================================
--- Zend/Service/Amazon/S3.php	(revision 21673)
+++ Zend/Service/Amazon/S3.php	(working copy)
@@ -190,6 +190,7 @@
      */
     public function isObjectAvailable($object)
     {
+        $object = $this->_fixupObjectName($object);
         $response = $this->_makeRequest('HEAD', $object);
 
         return ($response->getStatus() == 200);