[Zope] autologin with CookieCrumbler

Hi, as suggested in previous postings, I tried to log in via setting 2 cookies named ' __ac_name' and '__ac_password' providing username and password-info with CookieCrumbler. But despite I can verify the two cookies in the request, I get the loginform from CookieCrumbler and some query string in the url with something like 'disable_login=1'. Looking into the CookieCrumbler-Code it seems that this should be possible as the request is searched for the two cookies prior showing the loginform. Has anybody done this so far or are there any does and dont's to achiev this? thanks a lot, SK