In order to use Thrift with the Framework Symfony 2 and its great ClassLoader, I have:
namespaced your PHP Lib (phpsf2)
added an option sf2 to the PHP compiler. The main differences, are the use of namespace, and remove your autloader.
I have done this in the 0.8x branch (stable version) and in your trunk.
I use it with a Symfony bundle I create to have a cool integration in Symfony 2. Here is the git: email@example.com:ebuzzing/OverblogThriftBundle.git
Feel free to send me any question, any feedback on my pull request.