I've upgraded to ZF 1.5, and getting an error loading my form class.

This is my include path: set_include_path('.' . PATH_SEPARATOR . './library' . PATH_SEPARATOR . './applications/forms' . PATH_SEPARATOR . './application/models/' . PATH_SEPARATOR . get_include_path());

I've got my forms located here:
/application/forms

My file is called RegisterForm.php and the class name is: class RegisterForm extends Zend_Form

In my user controller I load it here: Zend_Loader::loadClass('RegisterForm');

The error I get is: Fatal error: Uncaught exception 'Zend_Exception' with message 'File "RegisterForm.php" was loaded but class "RegisterForm" was not found in the file' in /home/tplgame/public_html/library/Zend/Loader.php:88 Stack trace: #0 /home/tplgame/public_html/application/controllers/UsersController.php(110): Zend_Loader::loadClass('RegisterForm') #1 /home/tplgame/public_html/library/Zend/Controller/Action.php(502): UsersController->newAction() #2 /home/tplgame/public_html/library/Zend/Controller/Dispatcher/Standard.php(293): Zend_Controller_Action->dispatch('newAction') #3 /home/tplgame/public_html/library/Zend/Controller/Front.php(914): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http)) #4 /home/tplgame/public_html/index.php(49): Zend_Controller_Front->dispatch() #5 {main} thrown in /home/tplgame/public_html/library/Zend/Loader.php on line 88

Any help is greatly appreciated.