html - Why PHP include is working on local server and not on website

Problem Description in Brief:
PHP script seems to work on my local web server when I 'include' it from the footer tag of my index.html file, but does not work when I upload it to my website. Note that I have made sure that all paths are correct, and that the script file has its own php tags, etc.

Problem Description in Detail:
Yes, I am new to PHP scripting, and yes, variants of this question have probably been asked before. The answers to a few of the questions I have read have noted the path of the php script files to be incorrect. I have checked all paths and confirmed that they are indeed correct (including those on the web hosting server). Furthermore, I have been successful in getting the script to work on my local server running Apache2 with PHP5, but have not been successful when uploading it to my website.

Essentially, I am trying to implement a hit counter script which I have acquired from a post labelled Visitors counter for simple web sites like Vinaora. The code that invokes the php script looks something like this....

  <footer>
    <!-- Execute Hit Counter Script -->
    <?php include($_SERVER['DOCUMENT_ROOT'].'/php/hitcounter.php'); ?>
  </footer>

For the likes of me, I cannot figure out why it does not work on the web hosting server. I have tried other combinations of invoking the script like,

  <footer>

    <!-- Execute Hit Counter Script -->
    <?php include('./php/hitcounter.php'); ?>
  </footer>

and,

  <footer>
    <!-- Execute Hit Counter Script -->

    <?php include(dirname(__FILE__).'/php/hitcounter.php'); ?>
  </footer>

All combinations seem to work on my local web server, but not on the website! Also note that, I have no problem invoking other PHP scripts using other methods (even on the web hosting server), eg.

    <form id="form-query" onsubmit="this.checkValidity();" action="./php/contact.php" method="post">

Any advice/suggestions would be appreciated.