Zend & Ubuntu : zf.sh not working and raising exception
===

I have downloaded Zend framework and setup the installation as follows :

copied zf.sh & zf.php to /usr/bin (same location as /usr/bin/php)
copied Zend /library folder to /usr/share/php5/ZendFramework/library
php cli include_path = /usr/share/php5/ZendFramework/library
created an alias zf to /usr/bin/zf.sh

when I type zf show version I get this error :

    PHP Fatal error:  Uncaught exception 'Zend_Exception' with message 'File     "Zend/Tool/Project/Context/Zf/./ViewHelpersDirectory.php" does not exist or class "Zend_Tool_Project_Context_Zf_._ViewHelpersDirectory" was not found in the file' in /usr/share/php5/ZendFramework/library/Zend/Loader.php:99
    Stack trace:
    #0 /usr/share/php5/ZendFramework/library/Zend/Tool/Project/Context/Repository.php(88):     Zend_Loader::loadClass('Zend_Tool_Proje...')
    #1 /usr/share/php5/ZendFramework/library/Zend/Tool/Project/Context/Repository.php(79): Zend_Tool_Project_Context_Repository->addContextClass('Zend_Tool_Proje...')
    #2 /usr/share/php5/ZendFramework/library/Zend/Tool/Project/Provider/Abstract.php(85): Zend_Tool_Project_Context_Repository->addContextsFromDirectory('/usr/share/php5...', 'Zend_Tool_Proje...')
    #3 /usr/share/php5/ZendFramework/library/Zend/Tool/Framework/Provider/Repository.php(187): Zend_Tool_Project_Provider_Abstract->initialize()
    #4 /usr/share/php5/ZendFramework/library/Zend/Tool/Framework/Client/Abstract.php(128): Zend_Tool_Framewo in /usr/share/php5/ZendFramework/library/Zend/Loader.php on line 99

    Fatal error: Uncaught exception 'Zend_Exception' with message 'File "Zend/Tool/Project/Context/Zf/./ViewHelpersDirectory.php" does not exist or class "Zend_Tool_Project_Context_Zf_._ViewHelpersDirectory" was not found in the file' in /usr/share/php5/ZendFramework/library/Zend/Loader.php:99
    Stack trace:
    #0 /usr/share/php5/ZendFramework/library/Zend/Tool/Project/Context/Repository.php(88): Zend_Loader::loadClass('Zend_Tool_Proje...')
    #1 /usr/share/php5/ZendFramework/library/Zend/Tool/Project/Context/Repository.php(79): Zend_Tool_Project_Context_Repository->addContextClass('Zend_Tool_Proje...')
    #2 /usr/share/php5/ZendFramework/library/Zend/Tool/Project/Provider/Abstract.php(85): Zend_Tool_Project_Context_Repository->addContextsFromDirectory('/usr/share/php5...', 'Zend_Tool_Proje...')
    #3 /usr/share/php5/ZendFramework/library/Zend/Tool/Framework/Provider/Repository.php(187): Zend_Tool_Project_Provider_Abstract->initialize()
    #4 /usr/share/php5/ZendFramework/library/Zend/Tool/Framework/Client/Abstract.php(128): Zend_Tool_Framewo in /usr/share/php5/ZendFramework/library/Zend/Loader.php on line 99


Any help is appreciated.
Thanks.