Error: "Zend Optimizer Not installed"
<p>I got this error despite having Zend Optimizer installed.</p>

<blockquote>
  <p>Zend Optimizer not installed.In order to run it, please install the freely available Zend Optimizer, version 2.1.0 or later.</p>
</blockquote>

<p>I use PHP Version 5.2.5:</p>

<blockquote>
  <p>Zend Engine v2.2.0, Copyright (c) 1998-2007 Zend Technologies<br>
  with Zend Extension Manager v1.2.0, Copyright (c) 2003-2007, by Zend Technologies<br>
  with Zend Optimizer v3.3.0, Copyright (c) 1998-2007, by Zend Technologies</p>
</blockquote>
