Failed loading /usr/local/Zend/lib/ZendExtensionManager.so: /usr/local/Zend/lib/ZendExtensionManager.so: undefined symbol: zend_extensions
one of the most time consuming technical problem I have tackled today. php was not able to load Zend Optimizer due to mis configuration of Apache on the Linux cPanel
Dedicated Server.
I tried installing Zend Optimizer 3.0.2, 2.6.8 , 3.0.1 and 3.3.0Beta with no success. Zend Optimizer was working with php 4.4.6 but no success with PHP 5.0.4, php 5.1.2 or PHP 5.2.6. Finally I managed to figure out that versioning was enabled by someone from our end in php modules and I was using same default config in easyapache which elongated this problem.
Disabling versioning in easyapache sorted this problem. This solution will help many other people who will come across this problem.