Thank you for this bug report. To properly diagnose the problem, we
need a short but complete example script to be able to reproduce
this bug ourselves. 

A proper reproducing script starts with <?php and ends with ?>,
is max. 10-20 lines long and does not require any external 
resources such as databases, etc. If the script requires a 
database to demonstrate the issue, please make sure it creates 
all necessary tables, stored procedures etc.

Please avoid embedding huge scripts into the report.

use the script from the php documentation found here:
http://ch2.php.net/manual/en/function.ziparchive-extractto.php

<?php
$zip = new ZipArchive;
$res = $zip->open('test_im.zip');
if ($res === TRUE) {
   $zip->extractTo('/my/destination/dir/', array('pear_item.gif', 'testfromfile.php'));
   $zip->close();
   echo 'ok';
} else {
   echo 'failed';
}
?>

What is the actual result you get?

When I do:
$zip->extractTo('/my/destination/dir/');
every file in the archive is extracted.

When I do:
$zip->extractTo('/my/destination/dir/', 'pear_item.gif');
no file is extracted and no error message appear.

When I do:
$zip->extractTo('/my/destination/dir/', array('pear_item.gif','testfromfile.php'));
no file is extracted and no error message appear.

I cannot reproduce it on windows and unix, using CLI, apache2 , IIS or CGI.

What's the status after the extractTo call? Can you paste it here? do a var_dump($zip); after having called it.

I didn't know that the params of $zip->extractTo() are case sensitive, which is unusual for windows.
Nevertheless I have some cases, where the application hangs and I have to reboot the machine.
Give me some days to check this out.

Yes, it is case sensitive. It is in my todo to add a extended extract function. It will use the common flags (like ZIPARCHIVE::FL_NOCASE) or can based on special filters (like regexp or *.jpeg for example).

About your application hanging, it is a separate issue (if any), please open a new bug for it. I closed this one (bogus).