The previous problem with Zend Date was solved! Since we are using SVN, and I have committed it already to the server, I tried on on our main server. Everything works fine!
Therefore I conclude that my problem was only within the development server. After some time, I realized that my PHP version was 5.1.6 and the production server was 5.2.6. Although I always prefer to use lower (but mature) versions, I am forced to upgrade my dev box.
As opposed to the previous experience with installing PHP, it was now really easy! In just a few minutes, I have my project running. Unlike before, installing PHP would take 30 minutes to 1 hour.
Until next blog friends.