Update gui tool ends with failure of authen

[Harry Putnam <reader@newsguy.com>]

cat /etc/debian_version
    7.0
-------        ---------       ---=---       ---------      -------- 
I got here from an oldish wheezy install by setting my sources.list to
"testing" and running 
    aptitude update
    aptitude full-upgrade

The problem I'm about to describe was already there before the above
steps were done.

If I try to use the gui 'update software' tool It shows a few tiff
related files but ends with a failure of authentication.
(Note that before the upgrade I did try to overcome that by booting
into a root gui [I was not able to determine the name of the command
that starts the update tool from command line]).  But still failed so
apparently its not about root privs.

Here is what happens as my normal user:

I get a dialog box with the line below in large characters


        Additional confirmation required

 (Then the line below in smaller char)
To update these pkages, additional software also has to be modified

(The software shown in the dialog is) 

  "Tag Image File Format library (TIFF), devleopment files"

There is a "remove" tab that appears not to do anything and at the
bottom a cancel/continue set of buttons.

If I chose the Continue button, a new dialog pops up saying:
   Failed to precess request
Failed to obtain authentication
 
Due to my "full-upgrade" described above there are only 3 files needed
to be updated... all are tiff related.

Shouldn't the update tool prompt me for root passwd at some point when
I start it from a user account in X?
I haven't used it for a along while and not really remembering what is
supposed to happen.