There was absolutely no reason to downvote a post pointing out that software encoded for versions of Zend Optimizer/Zend Guard version 5.2 and below will not run on version 5.3 or higher; that was Zend's decision. If that is not the problem you are experiencing, that changes nothing about the veracity of my post. (I'd be tempted to get pretty ad hominem, and perhaps even vulgar, here if this weren't a family-friendly community.)