[TYPO3-seminars] redirect changes tx_seminars_pi1[seminars] to ?tx_seminars_pi1[uid]=3

[Basti Baumann]

Hi,

I´ve installed seminars with felogin.
If logged in registration of a seminar works fine.
If not logged in, I see the login page and in the url there are some 
redirect parameters:
http://www.domain.de/en/service-support/training/register-seminar/?tx_seminars_pi1%5Buid%5D=3&redirect_url=http%3A%2F%2Fwww.domain.de%2Fen%2Fservice-support%2Ftraining%2Fseminaranmeldung%2F%3Ftx_seminars_pi1%255Bseminar%255D%3D3%26tx_seminars_pi1%255Baction%255D%3Dregister

After login I stay at the same site and my parameters are gone away:
http://www.domain.de/en/service-support/training/register-seminar/?tx_seminars_pi1%5Buid%5D=3

so the param tx_seminars_pi1[action] is missing and the param 
tx_seminars_pi1[seminars] is changed to  tx_seminars_pi1[uid]

Why is that? If I manually type in the link the registration works...

Kind regards
Basti