title: PHP include_once not working for file in parent directory
body: <p>I just started working on a site that has been passed down to me that isn't working. I've found that there's a problem when in /admin/index.php it tries to instantiate an instance of /classes/admin.php. However, if I copy /admin/index.php to /admin-index.php, it can instantiate the class just fine. Also, if I move /classes/admin.php into /admin/classes/admin.php, I can also instantiate it just fine. There is at least one other class that I've noticed this with.</p>
  
  <p>I've also noticed that this isn't a problem on my local development machine. It's only an issue on the server.</p>
  
  <p>You can find info about the server at <a href="http://charlesekublyfoundation.org/admin/phpinfo.php" rel="nofollow noreferrer">http://charlesekublyfoundation.org/admin/phpinfo.php</a>. My development machine is a WinXP machine running Apache 2.2 and PHP 5.2.11 (Apache/2.2.14 (Win32) PHP/5.2.11 ).</p>
  
  <p>Has anyone seen anything like this? It seems odd. I'm fairly new to PHP development (primarily .NET developer), so I'm not sure what would cause this. I'm not sure if it's a difference in PHP or Apache or something else. </p>
  
  <p><strong>EDIT</strong>
  I should note that my server is running on some brand of Linux while by dev machine is Windows. I'm having a feeling that has something to do with this after looking into include_paths.</p>