Trouble in accessing `/home/USERNAME/.Xauthority'

[Tom H]

>> Because the authority has been moved to
>> /var/run/gdm/auth-...-<user>-.../database

> Ummm... worked just fine for me on the test 9.10 test machine.
> Further details please?

>From a brand new Karmic VM:
$ echo ${XAUTHORITY}
/var/run/gdm/auth-for-tomh0665-oM1IAa/database
$ ps -ef | grep X | grep -v grep
root ... tty7 ... /usrIbin/X ... -auth
/var/run/gdm/auth-for-gdm-kniKIS/database ...