I ran both commands as instructed.

However, the resulting var/log/pycentral.log is empty!

The output of sudo apt-get install was:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  stardict-common libdns50 libpcmanx-core0 stardict stardict-plugin-festival
  stardict-plugin-espeak pcmanx-gtk2 ttf-arphic-bsmi00lp ttf-arphic-gbsn00lp
  stardict-gtk imagemagick-doc libestools1.2 stardict-plugin gnuit
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
5 not fully installed or removed.
After this operation, 0B of additional disk space will be used.
Setting up medibuntu-keyring (2008.04.20) ...
dpkg (subprocess): unable to execute installed post-installation script: Exec format error
dpkg: error processing medibuntu-keyring (--configure):
 subprocess installed post-installation script returned error exit status 2
Setting up python2.5-minimal (2.5.4-1ubuntu6.1) ...
Linking and byte-compiling packages for runtime python2.5...
Traceback (most recent call last):
  File "/usr/bin/pycentral", line 2196, in <module>
    main()
  File "/usr/bin/pycentral", line 2190, in main
    rv = action.run(global_options)
  File "/usr/bin/pycentral", line 1746, in run
    pkg = DebPackage('package', pkgname, oldstyle=False)
  File "/usr/bin/pycentral", line 381, in __init__
    self.read_pyfiles()
  File "/usr/bin/pycentral", line 414, in read_pyfiles
    self.pkgconfig.set('pycentral', 'include-links', '0')
  File "/usr/lib/python2.6/ConfigParser.py", line 669, in set
    ConfigParser.set(self, section, option, value)
  File "/usr/lib/python2.6/ConfigParser.py", line 377, in set
    raise NoSectionError(section)
ConfigParser.NoSectionError: No section: 'pycentral'
dpkg: error processing python2.5-minimal (--configure):
 subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of python2.5:
 python2.5 depends on python2.5-minimal (= 2.5.4-1ubuntu6.1); however:
  PNo apport report written because the error message indicates its a followup error from a previous failure.
                             No apport report written because MaxReports is reached already
           No apport report written because MaxReports is reached already
                                                                         ackage python2.5-minimal is not configured yet.
dpkg: error processing python2.5 (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of python-gda:
 python-gda depends on python2.5 (>= 2.5); however:
  Package python2.5 is not configured yet.
dpkg: error processing python-gda (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of python-gnome2-extras:
 python-gnome2-extras depends on python-gda (= 2.25.3-3ubuntu1); however:
  Package python-gda is not configured yet.
dpkg: error processing python-gnome2-extras (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 medibuntu-keyring
 python2.5-minimal
 python2.5
 python-gda
 python-gnome2-extras
E: Sub-process /usr/bin/dpkg returned an error code (1)