the menu code on the page that is not working is not valid markup.
on the page where it is working, the nested li elements are properly closed where it is not working, they are not properly closed.
for example, on the page where the menu is not working, the menu code is:
<ul>
<li><a href="index.php" class="selected">Home</a></li>
<li><a href="about.php">Company</a>
<ul>
<li><span class="top"></span><span class="bottom"></span></li>
<li><a href="about.html">About Us</a></li>
<li><a href="portfolio.html">Portfolio</a></li>
<li><a href="development_team.html">Development Team</a></li>
</ul>
<li><a href="website_packages.php">Services</a>
<ul>
<li><span class="top"></span><span class="bottom"></span></li>
<li><a href="additional_services.html">Additional Services</a></li>
<li><a href="our_proccess.html">Client Process</a></li>
<li><a href="website_packages.html">Web Packages</a></li>
<li><a href="contract_Agreement.html">Contract</a></li>
</ul>
</li>
<li><a href="blog.php">Blog</a></li>
<li><a href="contact.php">Contact</a></li>
</ul>
in the code for the first nested menu for the company link:
<li><a href="about.php">Company</a>
<ul>
<li><span class="top"></span><span class="bottom"></span></li>
<li><a href="about.html">About Us</a></li>
<li><a href="portfolio.html">Portfolio</a></li>
<li><a href="development_team.html">Development Team</a></li>
</ul>
<li><a href="website_packages.php">Services</a>
the company li tag does not get closed, it should be:
<li><a href="about.php">Company</a>
<ul>
<li><span class="top"></span><span class="bottom"></span></li>
<li><a href="about.html">About Us</a></li>
<li><a href="portfolio.html">Portfolio</a></li>
<li><a href="development_team.html">Development Team</a></li>
</ul>
</li>
<li><a href="website_packages.php">Services</a>
