Laravel 身份验证筛选器在生产服务器上失败

我正在使用具有标准内置身份验证支持的Laravel 4框架。在本地环境中一切正常（MAMP，OSx），但是在我的生产服务器上（带有Ubuntu，Apache，Php 5.5.9的数字海洋标准映像）身份验证过滤器失败并允许未经身份验证的访问。

路线.php：

Route::group(['before'=>'auth'], function(){
    Route::get('admin', array('uses' => 'AdminController@home'));
    Route::get('admin/dashboard', function(){
        return Redirect::to('admin');
    });
    Route::post('payment/ok', array('uses' => 'PaymentController@ok'));
    Route::post('payment/fail', array('uses' => 'PaymentController@fail'));
    Route::get('admin/makeDMS/{id}', array('uses' => 'PaymentController@makeDMStransaction'));
    Route::get('admin/products', array('uses' => 'AdminController@products'));
    Route::get('admin/product/{id}', array('uses' => 'AdminController@product'));
    Route::get('admin/orders', array('uses' => 'AdminController@orders'));
    Route::get('admin/order/{id}', array('uses' => 'AdminController@order'));
    Route::post('admin/setOrderStatus', array('uses' => 'AdminController@setOrderStatus'));
    Route::post('admin/updateProduct', array('uses' => 'AdminController@updateProduct'));
    Route::get('admin/transactions', array('uses' => 'AdminController@transactions'));  
});

过滤器.php：

Route::filter('auth', function()
{
    if (Auth::guest())
    {
        if (Request::ajax())
        {
            return Response::make('Unauthorized', 401);
        }
        else
        {
            return Redirect::guest('login');
        }
    }
});

Route::filter('auth.basic', function()
{
    return Auth::basic();
});
Route::filter('guest', function()
{
    if (Auth::check()) return Redirect::to('/');
});

我尝试使用 Route::group 和控制器构造函数保护所需的路由，但输出是相同的：使用良好凭据登录有效，使用不良凭据的用户无法登录，但应该受到保护的路由组可供未经身份验证的用户使用。

我发现快速 CGI 模式下的 php 会产生这样的行为，但这是我sudo apachectl -M输出：

Loaded Modules:
 core_module (static)
 so_module (static)
 watchdog_module (static)
 http_module (static)
 log_config_module (static)
 logio_module (static)
 version_module (static)
 unixd_module (static)
 access_compat_module (shared)
 alias_module (shared)
 auth_basic_module (shared)
 authn_core_module (shared)
 authn_file_module (shared)
 authz_core_module (shared)
 authz_host_module (shared)
 authz_user_module (shared)
 autoindex_module (shared)
 deflate_module (shared)
 dir_module (shared)
 env_module (shared)
 filter_module (shared)
 mime_module (shared)
 mpm_prefork_module (shared)
 negotiation_module (shared)
 php5_module (shared)
 rewrite_module (shared)
 setenvif_module (shared)
 status_module (shared)