Description:
------------
Once a SplFileObject instance was created​​, filemtime() does not return the latest 
modification time of the file.

Test script:
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filemtime.php
<?php

$file = '/tmp/test';
touch($file);
$fileObject = new SplFileObject($file); // If comment out this line, it works well.
touch($file, time() + 1);

echo 'time():                      ' . date('Y-m-d H:i:s', time()) . PHP_EOL;
echo 'time() + 1:                  ' . date('Y-m-d H:i:s', time() + 1) . PHP_EOL;
echo 'filemtime($file):            ' . date('Y-m-d H:i:s', filemtime($file)) . PHP_EOL;
echo 'filemtime($file)@subprocess: ';
passthru('php -r "echo date(\'Y-m-d H:i:s\', filemtime(\'/tmp/test\')) . PHP_EOL;"');


Expected result:
----------------
$ php filemtime.php 
time():                      2012-03-04 18:37:01
time() + 1:                  2012-03-04 18:37:02
filemtime($file):            2012-03-04 18:37:02
filemtime($file)@subprocess: 2012-03-04 18:37:02

Actual result:
--------------
$ php filemtime.php 
time():                      2012-03-04 18:37:01
time() + 1:                  2012-03-04 18:37:02
filemtime($file):            2012-03-04 18:37:01
filemtime($file)@subprocess: 2012-03-04 18:37:02