Running an Old Kernel Solved.

[Martin McCormick]

	There is a /etc/pam.d and a /usr/local/etc/pam.d.
/etc/pam.d has no sudo file in it but /usr/local/etc/pam.d does.
I had never edited that file before but it seems to change
slightly in 2007. 
The sudo file on the system that did not display the "last
login" message has a modification date of December 20, 2007 and
sudo, itself also has that date.

Here is that file.

#
# $Id$
#
# PAM configuration for the "sudo" service
#

# auth
auth		include		system

# account
account		include		system

# session
# XXX: pam_lastlog (used in system) causes users to appear as though
# they are no longer logged in in system logs.
session		required	pam_permit.so

# password
password	include		system

This line makes the difference.

# XXX: pam_lastlog (used in system) causes users to appear as though
# they are no longer logged in in system logs.

This version effectively has no include  system directive for
that file.

	The system that did display the "last login" message had
a pam.d/sudo file dated July of 2007. /usr/local/bin/sudo had a
modification date of April 8 of 2008. I may have removed sudo
and reinstalled it to try to get rid of the problem but I
obviously did not also get a new /usr/local/etc/pam.d/sudo file
which would probably have been the only change necessary.

Here is the older file.

#
# $Id$
#
# PAM configuration for the "sudo" service
#

# auth
auth		include		system

# account
account		include		system

# session
session		include		system

# password
password	include		system

Here's the big difference.

session		include		system

As soon as I commented it out, the problem went away.

	One needs to be xtremely careful in not restoring the
old /usr/local/pam.d directory when building a new system and
restoring files from the old system. I have been chasing this
monster since the Summer of 2007. The new 8.0 system is
presently turned off but I bet when I look at it on Monday, it
has the 2007 /usr/local/etc/pam.d directory since I completely
forgot about making sure it didn't get in to the new system.

Martin McCormick