must be an error in Phalcon 2.1.0 in Windows, both quotes duplicate namespace, and no namespace it goes to the frontend module
$router->addModuleResource ( "quest", "Category" );
Class Web\Frontend\Controllers\CategoryController does not exist
end
$router->addModuleResource ( "quest", "/Web/Quest/Controllers/Category" );
Class \Web\Quest\Controllers\/Web/Quest/Controllers/CategoryController does not exist
end
$router->addModuleResource ( "quest", "Web/Quest/Controllers/Category" );
Class \Web\Quest\Controllers\Web/Quest/Controllers/CategoryController does not exist