gksudo reports "authenication rejected - none of the protocols specified are supported and host-base failed".. I have reinstalled Ubuntu 7.04 four times, get same message

Binary package hint: gnome-terminal

nautilus:5297): GnomeUI-WARNING **: While connecting to session manager:
Authentication Rejected, reason : None of the authentication protocols specified are supported and host-based authentication failed.
Initializing gnome-mount extension

I have reinstalled the operating system several times. After as few as 20 minutes and up to maybe an hour or so, gksudo nautilus works, then I start getting this message and I no longer log into root using gksudo. The only thing I have done after installing the operating system is install a printer, a scanner, and set up sharing on a windows local network. I am using Ubuntu 7.04 updated to the latest fixes.

Don

ProblemType: Bug
Architecture: i386
Date: Thu Oct 11 22:59:08 2007
DistroRelease: Ubuntu 7.04
ExecutablePath: /usr/bin/gnome-terminal
Package: gnome-terminal 2.18.0-0ubuntu1
PackageArchitecture: i386
ProcCmdline: gnome-terminal
ProcCwd: /home/don
ProcEnviron:
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-terminal
Uname: Linux P833 2.6.20-16-generic #2 SMP Sun Sep 23 19:50:39 UTC 2007 i686 GNU/Linux