Zend Optimizer howto install

[spycat]

Hello, i was try to install Zend Optimizer on ISPCP and after i put php -v i see that:

PHP 5.2.6-1+lenny3 with Suhosin-Patch 0.9.6.2 (cli) (built: Apr 26 2009 20:09:03)
Copyright © 1997-2008 The PHP Group
Zend Engine v2.2.0, Copyright © 1998-2008 Zend Technologies
with the ionCube PHP Loader v3.3.1, Copyright © 2002-2009, by ionCube Ltd., and
with Zend Optimizer v3.3.9, Copyright © 1998-2009, by Zend Technologies

but when i opened web page there is information: Zend Optimizer not installed, my question is why?