Lets us check which php version is installed.

In your favorite editor create a file named phpinfo.php and put this line into that file:

PHP Code:
<?php phpinfo(); ?>
Save that file and upload it via FTP to the root of your ZC installation - eg:

yourdomain.com/phpinfo.php

Then open your browser and call http://yourdomain.com/phpinfo.php

Let us know what the heading for that file reads, the heading should show something like this:

PHP Version 5.x.xx

Please post the result here.