The range headers should read

0-8191 for the first 8192 bytes, instead we send 0-8192

To test:

<?php

define('AWS_KEY', 'a key');
define('AWS_SECRET_KEY', 'a secret');

require_once 'Zend/Service/Amazon/S3.php';

$s3 = new Zend_Service_Amazon_S3(AWS_KEY, AWS_SECRET_KEY);

$s3->registerStreamWrapper("s3");

copy('./test.pdf', 's3://bucket-name/test.pdf');
copy('s3://bucket-name/test.pdf', 'test2.pdf');

var_dump(file_get_contents('test.pdf') == file_get_contents('test2.pdf'));

Simple patch

Index: Zend/Service/Amazon/S3/Stream.php
===================================================================
--- Zend/Service/Amazon/S3/Stream.php   (revision 22829)
+++ Zend/Service/Amazon/S3/Stream.php   (working copy)
@@ -194,7 +194,7 @@
         }
 
         $range_start = $this->_position;
-        $range_end = $this->_position+$count;
+        $range_end = $this->_position+$count-1;
 
         // Only fetch more data from S3 if we haven't fetched any data yet (postion=0)
         // OR, the range end position is greater than the size of the current object