I've been using aptitude for years without a problem, and the system upgrade
was not done with aptitude.
The upgrade was started from a dialog that kept popping up asking me to
upgrade the system.
That upgrade stopped and supposedly ran a "recovery", although I did not see
anything further happen.
I ran aptitude because that's what I've always used in the past.

I've reinstalled gnome-panel and upuntu-desktop and fglrx.  I don't know
what else might be broken, or even how to tell, except that everything
related to the wine has become inoperative.

I've opened a bug report for that at
https://bugs.launchpad.net/ubuntu/+bug/880640

On Mon, Oct 24, 2011 at 12:30 PM, Steve Langasek <
<email address hidden>> wrote:

> aptitude is not the recommended interface for commandline-based
> upgrades; it's recommended that you use apt-get instead.  And aptitude
> is known to not work right with multiarch packages (which is what
> libpam-modules:i386 is).  I'm sorry, but it sounds like aptitude has
> made a real mess of your system.
>
> You may be able to fix this by running 'sudo apt-get install ubuntu-
> desktop'.  But if that doesn't solve it, I think you'll want to take
> this question to one of the support forums. (ubuntuforums.org,
> askubuntu.com, etc)
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/871083
>
> Title:
>  package libpam-modules 1.1.3-2ubuntu1 failed to install/upgrade:
>  ErrorMessage: './usr/share/man/man8/pam_shells.8.gz' is different from
>  the same file on the system
>
> Status in “pam” package in Ubuntu:
>  Fix Committed
> Status in “pam” source package in Oneiric:
>  Fix Committed
>
> Bug description:
>  SRU justification:
>  libpam-modules is not multiarch-coinstallable because of unexplained
> misgeneration of compressed manpages on the buildds in a previous run.  This
> makes it impossible to use pam authentication for foreign-arch software due
> to the uninstallable modules, and also causes unpleasant upgrade issues.
>
>  Test case:
>  1) on amd64, enable armel in addition to i386 as a foreign architecture by
> running:
>    echo 'foreign-architecture armel' >>
> /etc/dpkg/dpkg.cfg.d/multiarch-armel
>    echo 'deb [arch=armel] http://ports.ubuntu.com/ubuntu-ports/ oneiric
> main' >> /etc/apt/sources.list
>    apt-get update
>  2) try to install libpam-modules for the other two architectures by
> running 'apt-get install libpam-modules:i386 libpam-modules:armel'
>  3) confirm that both packages fail to install.
>  4) enable oneiric-proposed (including for armel above).
>  5) try to install libpam-modules for all three architectures by running
> 'apt-get install libpam-modules libpam-modules:i386 libpam-modules:armel'
>  6) confirm that the packages install successfully.
>
>  error while updating
>
>  ProblemType: Package
>  DistroRelease: Ubuntu 11.10
>  Package: libpam-modules 1.1.3-2ubuntu1
>  ProcVersionSignature: Ubuntu 2.6.38-11.50-generic 2.6.38.8
>  Uname: Linux 2.6.38-11-generic x86_64
>  NonfreeKernelModules: wl
>  ApportVersion: 1.23-0ubuntu2
>  Architecture: amd64
>  Date: Sat Oct  8 18:57:52 2011
>  ErrorMessage: ErrorMessage: './usr/share/man/man8/pam_shells.8.gz' is
> different from the same file on the system
>  InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64
> (20110427.1)
>  SourcePackage: pam
>  Title: package libpam-modules 1.1.3-2ubuntu1 failed to install/upgrade:
> ErrorMessage: './usr/share/man/man8/pam_shells.8.gz' is different from the
> same file on the system
>  UpgradeStatus: Upgraded to oneiric on 2011-10-09 (0 days ago)
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/ubuntu/+source/pam/+bug/871083/+subscriptions
>