12.04 LTS, on a dell mini 10. Install stable until about a week ago. Updated about 1x a week, sometimes more often. Several days ago, I booted up and the system was no longer working correctly. All these symptoms occurred simultaneously: Cannot run (exit on opening, every time): Update manager, software center, ubuntuOne, libreOffice. Vinagre autostarts on boot, no explanation, not set to startup with Ubuntu.

Using apt-get to fix install results in the following:

maura@pandora:~$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Correcting dependencies... Done
The following package was automatically installed and is no longer required:
  libtelepathy-farstream2
Use 'apt-get autoremove' to remove them.
The following extra packages will be installed:
  gwibber gwibber-service kde-runtime-data software-center
Suggested packages:
  gwibber-service-flickr gwibber-service-digg gwibber-service-statusnet
  gwibber-service-foursquare gwibber-service-friendfeed gwibber-service-pingfm
  gwibber-service-qaiku unity-lens-gwibber
The following packages will be upgraded:
  gwibber gwibber-service kde-runtime-data software-center
4 upgraded, 0 newly installed, 0 to remove and 39 not upgraded.
20 not fully installed or removed.
Need to get 0 B/5,682 kB of archives.
After this operation, 177 kB of additional disk space will be used.
Do you want to continue [Y/n]? 
debconf: Perl may be unconfigured (Can't locate Scalar/Util.pm in @INC (@INC contains: /etc/perl /usr/local/lib/perl/5.14.2 /usr/local/share/perl/5.14.2 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.14 /usr/share/perl/5.14 /usr/local/lib/site_perl .) at /usr/lib/perl/5.14/Hash/Util.pm line 9.
BEGIN failed--compilation aborted at /usr/lib/perl/5.14/Hash/Util.pm line 9.
Compilation failed in require at /usr/share/perl/5.14/fields.pm line 122.
Compilation failed in require at /usr/share/perl5/Debconf/Log.pm line 10.
Compilation failed in require at (eval 1) line 4.
BEGIN failed--compilation aborted at (eval 1) line 4.
) -- aborting
(Reading database ... 242672 files and directories currently installed.)
Preparing to replace gwibber 3.4.1-0ubuntu1 (using .../gwibber_3.4.2-0ubuntu1_i386.deb) ...
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
dpkg: warning: subprocess old pre-removal script returned error exit status 1
dpkg - trying script from the new package instead ...
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
dpkg: error processing /var/cache/apt/archives/gwibber_3.4.2-0ubuntu1_i386.deb (--unpack):
 subprocess new pre-removal script returned error exit status 1
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pycompile", line 27, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pycompile", line 27, in <module>
    import logging
ImportError: No module named logging
dpkg: error while cleaning up:
 subprocess installed post-installation script returned error exit status 1
Preparing to replace gwibber-service 3.4.1-0ubuntu1 (using .../gwibber-service_3.4.2-0ubuntu1_all.deb) ...
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
dpkg: warning: subprocess old pre-removal script returned error exit status 1
dpkg - trying script from the new package instead ...
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
dpkg: error processing /var/cache/apt/archives/gwibber-service_3.4.2-0ubuntu1_all.deb (--unpack):
 subprocess new pre-removal script returned error exit status 1
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pycompile", line 27, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pycompile", line 27, in <module>
    import logging
ImportError: No module named logging
dpkg: error while cleaning up:
 subprocess installed post-installation script returned error exit status 1
Preparing to replace kde-runtime-data 4:4.8.3-0ubuntu0.1 (using .../kde-runtime-data_4%3a4.8.4-0ubuntu0.1_all.deb) ...
Unpacking replacement kde-runtime-data ...
dpkg: error processing /var/cache/apt/archives/kde-runtime-data_4%3a4.8.4-0ubuntu0.1_all.deb (--unpack):
 trying to overwrite '/usr/share/sounds', which is also in package sound-theme-freedesktop 0.7.pristine-2
dpkg-deb (subprocess): subprocess data was killed by signal (Broken pipe)
dpkg-deb: error: subprocess <decompress> returned error exit status 2
Preparing to replace python-crypto 2.4.1-1 (using .../python-crypto_2.4.1-1_i386.deb) ...
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
dpkg: warning: subprocess old pre-removal script returned error exit status 1
dpkg - trying script from the new package instead ...
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
dpkg: error processing /var/cache/apt/archives/python-crypto_2.4.1-1_i386.deb (--unpack):
 subprocess new pre-removal script returned error exit status 1
No apport report written because MaxReports is reached already
                                                              Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pycompile", line 27, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pycompile", line 27, in <module>
    import logging
ImportError: No module named logging
dpkg: error while cleaning up:
 subprocess installed post-installation script returned error exit status 1
Preparing to replace software-center 5.2.2.2 (using .../software-center_5.2.4_all.deb) ...
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
dpkg: warning: subprocess old pre-removal script returned error exit status 1
dpkg - trying script from the new package instead ...
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
dpkg: error processing /var/cache/apt/archives/software-center_5.2.4_all.deb (--unpack):
 subprocess new pre-removal script returned error exit status 1
No apport report written because MaxReports is reached already
                                                              Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pycompile", line 27, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pycompile", line 27, in <module>
    import logging
ImportError: No module named logging
dpkg: error while cleaning up:
 subprocess installed post-installation script returned error exit status 1
Preparing to replace xdiagnose 2.5 (using .../archives/xdiagnose_2.5_all.deb) ...
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
dpkg: warning: subprocess old pre-removal script returned error exit status 1
dpkg - trying script from the new package instead ...
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pyclean", line 25, in <module>
    import logging
ImportError: No module named logging
dpkg: error processing /var/cache/apt/archives/xdiagnose_2.5_all.deb (--unpack):
 subprocess new pre-removal script returned error exit status 1
No apport report written because MaxReports is reached already
                                                              Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/usr/bin/pycompile", line 27, in <module>
    import logging
ImportError: No module named logging
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 64, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
    from apport.report import Report
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 16, in <module>
    from xml.parsers.expat import ExpatError
  File "/usr/lib/python2.7/xml/parsers/expat.py", line 4, in <module>
    from pyexpat import *
ImportError: No module named pyexpat

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pycompile", line 27, in <module>
    import logging
ImportError: No module named logging
dpkg: error while cleaning up:
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 /var/cache/apt/archives/gwibber_3.4.2-0ubuntu1_i386.deb
 /var/cache/apt/archives/gwibber-service_3.4.2-0ubuntu1_all.deb
 /var/cache/apt/archives/kde-runtime-data_4%3a4.8.4-0ubuntu0.1_all.deb
 /var/cache/apt/archives/python-crypto_2.4.1-1_i386.deb
 /var/cache/apt/archives/software-center_5.2.4_all.deb
 /var/cache/apt/archives/xdiagnose_2.5_all.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
maura@pandora:~$ ^C
maura@pandora:~$