[Zope] PHPGateway Issues

Hello. I am trying to use PHPGateway with Zope but I get the following error: '/usr/bin/php' may not be a PHP-CGI program. The result from the program is empty(0 byte). Also, sometimes I get the error 'File Not Found' that is thrown by the browser. Has anyone successfully used this product with Zope and are there documents which cover common errors and solutions? Lastly, I am running on Mac OS X Tiger Server which comes with PHP 4 and I am running Zope 2.7.0. Can I use this copy of PHP or do I have to download and build my own from source? Any help would be appreciated. Thanks.