[Flow] Authentication problem: Login-form after POST request

[Mathis Hoffmann]

Hello,

I've introduced authentication some days ago and encounter the following 
problem now: Everytime after submitting a form (so after a post request) 
the login-form is redisplayed. But the user is not logged out. If I call 
another protected controller method manually by entering the url 
(without resubmitting the login-form) the login-form is not displayed. I 
really do not know why that happens. All controllers are directly 
located unter \HdM\Accounting\Controller. The policy-file is really simple:

roles:
   User: []

resources:
   methods:
     allProtectedMethods: 'method(HdM\Accounting\Controller\.*->.*()) && 
!method(HdM\Accounting\Controller\AuthenticationController->.*())'

acls:
   User:
     methods:
       allProtectedMethods: GRANT

Does anyone have an idea why that happens? Everything else works like it 
should.

Cheers
Mathis