Laravel 4.1 ReflectionException

I get the following error from Laravel 4.1.

ReflectionException Class Acme\Services\TaskCreatorService does not exist.

Thanks in advance for any help.

Below is the code defining the class. It is found in app\Acme\Services.

<?php namespace Acme\Services;

use \Acme\Validators\TaskValidator;
use \Acme\Validators\ValidationException;
use \Acme\Validators\Validator;

class TaskCreatorService {

    protected $validator;

    public function __construct(TaskValidator $validator) {

        $this->validator = $validator;

    }

    public function make(array $attributes) {

        //determone whether data is valid
        if ($this->validator->isValid($attributes)) {
        Task::create([
            'title' => $attributes['title'],
            'body' => $attributes['body'],
            'user_id' => $attributes['assign']
         ]);

        return true;
        }

        throw new ValidationException('Task validation failed', $this->validator-getErrors());
        //create the new task
        //
        //if not throw exception
    }
}

I have also add this to composer.json in the autoload section.

    "psr-0": {
        "Acme": "app/"
    }