I recently upgraded my server to ubuntu 11.04. IF I remember correctly, I accidentally said keep my current version of some /etc/security/something.conf. Now whenever I try to login with ssh, I get successfully authenticated, then immediately kicked off. I looked in the logs, and it says pam_open_session(): Module is unknown. i think this may have something to do with my security conf file not being upgraded to the package maintainer's version, but not sure. Any help is appreciated.