cannot load ubuntu 9.10 and it shows "could not update ICEauthority"

if you found this error appear "could not update ICEauthority" on ubuntu 9.10 here is what you do....

1. boot into recovery mode (read previously entry "how to boot to ubuntu recovery mode")
2. select option root -- drop to root shell prompt and press enter
3. type >> login
4. you will get this prompt:
-desktop login: enter you user account name
password: enter your password (NOTE: you will not see the characters that you type here)
5. at the next prompt type:
startx
6. This will log you into your normal user account. The Login Screen menu item will be accessable at this point but, it will not work.

7. in a terminal window enter this command:
sudo gedit

8. enter your password when prompted. This will open gedit with root permissions.

9. in gedit click open then under file system browse to /ect/gdm/custom.conf

10. you should see a file that looks like this:
[daemon]
TimedLoginEnable=false
AutomaticLoginEnable=true
TimedLogin=craig
AutomaticLogin=craig
TimedLoginDelay=30

11. simply change AutomaticLoginEnable=true to =false

12. shutdown as normal. this will drop you back into the recovery mode. Close out from that and restart. From there everything should be good.

credit to : Craig Bakkala from http://swiss.ubuntuforums.org