In case you are using a combination of Authlogic, Cucumber and the CookieSessionStore, be very careful with your domain configuration. As our project is working with various subdomains, we are using /etc/hosts with an .local extension on our dev machines. But be careful with the settings. In rails3 you are not supposed to set the session store in the environment config files, but in an initializer. If you are not careful and define a domain for cucumber, you might get into trouble, as it uses www.example.com internally. And all the cookies you are setting are invalid.
I should have thought about it earlier, but at least I found my mistake :(
