When I was booting a new Ubuntu 10.10 installation, I got an error message, "Could not update ICEauthority file /home/ray/.ICEauthority." I clicked through that, checked Update Manager, and rebooted. The ICEauthority error message was there again.
Seeking answers to this problem, I ran a search and tried the suggestion to type Ctrl-Alt-F1 to get a text console. There, I hit Enter to get a login prompt. I logged in with my username and password, and this gave me a regular command prompt. I typed "sudo chown -R ray:ray .ICEauthority," where ray was my username. Then I typed "sudo /etc/init.d/gdm restart" to go back into the Gnome GUI. But the ICEauthority error message was still there. (From another post, it appears I could have just entered the chown command in Terminal, without Ctrl-Alt-F1.) People for whom this approach worked seemed to think that the problem was caused by opening a graphical (i.e., not purely text-based) program owned by root using sudo instead of gksudo. If that was relevant, it evidently meant I should have edited fstab by typing "gksudo gedit /etc/fstab." But was gedit a graphical program? Probably the better explanation was that my problem was caused by something else, and that this is why their solution didn't work for me.
Comments in another thread suggested that the problem might have been caused by an update, and also that the chown command (above) wouldn't work on an encrypted home partition. In a variation, I tried this:
sudo -iBut this didn't do it either; the error was back when I rebooted. Somebody else said the problem had to do with changing passwords, and that was possibly relevant for me, so I went into System > Administration > Users and Groups and changed my user password, and also checked the box that said, "Don't ask for password on login." But Ubuntu hung when I clicked OK; the circle icon (like the Windows hourglass, meaning "I'm working on it") stayed there for a couple of hours. When I came back to the machine, I killed the dialog box and tried changing the password again, but it hung again. I ran a search on that subproblem and tried the advice to kill that GUI approach and just type "sudo passwd [username]" in Terminal (my username was ray). That worked. So, back to the ICEauthority problem. I rebooted, but no, the password fix was not the solution; the error message was still there.
chown ray:ray /home/ray/.ICEauthority
chmod 644 /home/ray/.ICEauthority\
Another suggestion was to make sure that the entire home directory belonged to the user (me). That sounded like it might be on the money. My impression was that moving around and copying this old /home partition could easily have screwed up the permissions. So now, how to make sure I owned the whole /home directory? In Nautilus (i.e., Places > Computer), I right-clicked on Home Folder > Properties > Permissions. It said root (i.e., not ray) was the owner. In Terminal, I typed "sudo nautilus" and, using the Tree (i.e., not Places) view (top of left panel), went to File System > home > ray > right-click Properties > Permissions and changed the permissions to me with full access. I clicked on the "Apply Permissions to Enclosed Files" button, closed out of there, and rebooted. Eureka! That was the solution. Done!