Your style sheets are in the protected area aren't they?
The J_Secutity_check will try to re-direct you to the last secured url your page tried to access....in this case the stylesheet for the login page itself. If you put a copy of the style sheet outside the secured area for the login, it should work.
Ok I created new module "authentification" and i moved all the required files there. How can I set that this modul is not secured? Than you very much. Paja.
What does your Security contrriants in you web.xml look like? If the URL pattern is /* then clearly your /resources/style.css is in the protected area (/* matches with /resources).
Simply make your security contraint witha URL patter n like /secure/* and place your ligin .jsp and style sheets out side of this directory