Comment 12 for bug 432492

I am also getting:
   I- [Could not update ICEauthority file /var/lib/gdm/.ICEauthority]
   II- [This is a problem with the configuration sever.
        (usr/lib/libgconf2-4/gconf-sanity-check-2 exited with status 256)]
except I am able to login for each user on the system after clicking 'OK' on the warning popups.

If I open Nautilus as root (gksu nautilus) and look at the permissions properties, on the machine with errors I show permissions for /var/lib/gdm/.ICEAuthority as:

Owner: avahi-autopd - Avahi autoip daemon
Access: Read and write
Group: fuse
Access: None
Others
Access: None
SELinux context: unknown
Last changed: unknown

$ apt-cache policy gdm
gdm:
  Installed: 2.28.1-0ubuntu2
  Candidate: 2.28.1-0ubuntu2
  Version table:
 *** 2.28.1-0ubuntu2 0
        500 http://archive.ubuntu.com karmic-updates/main Packages
        100 /var/lib/dpkg/status
     2.28.1-0ubuntu1 0
        500 http://archive.ubuntu.com karmic/main Packages

$ uname -a
2.6.31-15-generic #50-Ubuntu SMP Tue Nov 10 14:54:29 UTC 2009 i686 GNU/Linux

Note: the machine has been updated from dapper thru karmic & the hard drives changed from 40Gb to 200Gb using Gparted 'copy'.

If I look at the permissions for /var/lib/gdm/.ICEAuthority on a clean karmic install (with no errors), I see that .ICEAuthority has the same Owner and Group as the /var/lib/gdm folder:

Owner: gdm - Gnome Display Manager
Access: Read and Write
Group: gdm
Access: none
Others
Access: None

The exception of course is the Access for Group is set to 'none' on the file and 'Access files' on the folder.