Laravel partial mocks not working with repository pattern

Been going in circles for a while, and I hope somebody can get me going again...

I'm writing phpunit unit tests for a Laravel 4.2 controller function but get an error telling me that a function doesn't exist on my mock object.

Here's the controller:

use My\Storage\Cond\CondInterface as Cond;

class CondRuleController extends \BaseController {

protected $rule;

public function __construct(Cond $rule)
{
    $this->rule = $rule;
}

public function store()
{
    // Limit input input
    $post = Input::only('A','B','C');

    // Calculate and add another value
    $post['D'] = $this->rule->nextOrder($post['A']);

    // Try to create the rule or throw error
    $this->rule = $this->rule->create($post);
    if($this->rule->errors) throw new Exception('nope!');

    return View::make('success_view');          
}

And the interface:

namespace My\Storage\Cond;

interface CondInterface {

    public function nextOrder($value);
    public function create($data);
    ...
}

And the Eloquent repository (bound to interface in a Service Provider not shown here):

namespace My\Storage\Cond;

use My\Storage\Cond\CondInterface;
use Cond;

class CondEloquentRepository implements CondInterface {

    protected $rule;

    public function __construct(Cond $rule) 
    {
        $this->rule = $rule;
    }

    public function nextOrder($value)
    {
        $max = $this->rule->whereValue($value)->max('order');
        return (empty($max)) ? 1 : $max + 1;
    }

    // Use Eloquent create() method
    public function create($post)
    {
        return $this->rule->create($post);
    }
    ...
}

Cond is a pretty standard Eloquent model.

And my test:

class CondRuleControllerTest extends TestCase {

    public function setUp() 
    {
        parent::setUp();
        $this->mock = Mockery::mock("My\Storage\Cond\CondInterface")->makePartial();
        $this->controller = new CondRuleController($this->mock);

        // Set up passing defaults
        $this->input = array('A' => 'red', 'B' => 'blue','C' => 'green');
        Input::replace($this->input);

        // Extended results following nextOrder
        $this->create_data = array('A' => 'red', 'B' => 'blue','C' => 'green', 'D' => 1);
    }
    public function tearDown()
    {
        Mockery::close();
    }

    public function testStoreOK() 
    {
        $this->mock->shouldReceive('nextOrder')
                    ->once()
                    ->with('red')
                    ->andReturn(1);

        $this->mock->shouldReceive('create')
                   ->once()
                   ->with($this->create_data)
                   ->andReturn($this->mock);

        View::shouldReceive('make')->once()->with('success_view');

        $this->controller->store();
    }

When I run this, then I get the following error:

1) CondRuleControllerTest::testStoreOK
   BadMethodCallException: Method Mockery_0_My_Storage_Cond_CondInterface::create() does not exist on this mock object

I'm confused why create() doesn't appear to be mocked correctly, but nextOrder() does. Perhaps it is clashing with Eloquent's create()?

On a seperate (unrelated) note, I found that removing the with() statement in the second shouldReceive() makes the test pass, but with zero assertions.

Any suggestions gratefully received!