we have found out that in some cases the authentication daemon gets not restarted properly. So far this seems to only happen on slower machines.
Can you give us information what kind of hardware has been used (CPU, RAM, RAM/SWAP usage) in the system where the login was no longer possible after the reboot?
as an alternative to rebooting you can also log into the box via SSH and do /etc/init.d/aua start
This will start the authentication daemon and the login is than possible again.
I think we found the issue: for slower boxes the default timeout for stopping the authentication daemon was not sufficient and in combination with a race condition while (re-)starting it may result in the scenario you described. All mentioned workarounds are valid (reboot or restart the daemon), nevertheless we changed the initscript within the package for users who did not install it yet. In case you already installed it, don't worry - everything should continue working normally. We'll readd this little change also in the next package to make sure everyone is running the same version of the scripts.
Marcel, I haven't installed the update yet, but it looks like my firewall has already downloaded it. Can I delete it and re-download? I'm running on a PIII with 512MB so I'm betting that may be a "slower box". [:P]