Namespace problem with Form Type

[bolbo]

Hi,
I have a Symfony2.6 application with a form Type in src/Acme/DemoBundle/Form/Type/ArticleType.php

When I write the test for this form type, I create file src/Acme/DemoBundle/Tests/Units/Form/Type/ArticleTypeTest.php
In this file, if I set namespace:
namespace Acme\DemoBundle\Tests\Units\Form\Type;

and I run the test I have this error:

Running duration: 6.71 seconds.
Failure (2 tests, 1/2 methods, 1 void method, 0 skipped method, 0 uncompleted method, 0 failure, 1 error, 0 exception)!

There is 1 error:
=> Acme\DemoBundle\Tests\Units\Form\Type\ArticleType::testFormType():
==> Error E_USER_ERROR in /sf2-propel-atoum/src/Acme/DemoBundle/Tests/Units/Form/Type/ArticleTypeTest.php on unknown line, generated by unknown file:
Tested class 'Acme\DemoBundle\Units\Form\Type\ArticleType' does not exist for test class 'Acme\DemoBundle\Tests\Units\Form\Type\ArticleType'

If I set namespace: namespace Acme\DemoBundle\Tests\Form\Type;
there is no error

https://github.com/lbol/sf2-propel-atoum/blob/master/src/Acme/DemoBundle/Form/Type/ArticleType.php
https://github.com/lbol/sf2-propel-atoum/blob/master/src/Acme/DemoBundle/Tests/Units/Form/Type/ArticleTypeTest.php