Ubuntu 9.10 - Auto user login

The automatich user Login, which you can turn on in System -> System -> Logon Screen is not stable. I turned off my PC and in the morning an Error appeared. You have to go into the console-mode by pressing Strg+Alt+F1, restart your GDM by typing: sudo /etc/init.d/gdm restart and then you have to give 655-privileges to the file mentioned in the error. After that your system should boot again.