[TYPO3-mvc] Realurl and hmac

[Sebastian Fischer]

Hi everyone,

i tried to configure realurl for controller and action in use with a 
form. But everything i get is:

#1255082824: Request hash (HMAC) checking failed. The parameter __hmac 
was invalid or not set, and objects were modified.

Whenever i remove the setting and the parameters are present in the url 
als get parameters everything works fine. As soon as i activate the 
rewriting i get that error after sending the form.

What is the problem there and how can i fix it?

Greetings
Sebastian