Problema grafico con Ubuntu Software-Center

Salve a tutti, da quando ho installato la versione 14.04 lts di Ubuntu ho questo problema con il software-center. In sostanza la grafica è tutta "rovinata", si riescono a distinguere a malapena i nomi delle varie app in vendita, per non parlare poi dell'elenco delle app installate che è praticamente non visibile, non è molto facile da spiegare, ma è come se ci sia il contrasto sballatissimo. Lanciandolo da terminale vengono visualizzate tutta una serie di messaggi che vi riporto qui di seguito:

2015-03-10 19:13:50,182 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None'
2015-03-10 19:13:50,340 - softwarecenter.region - WARNING - failed to use geoclue: 'org.freedesktop.DBus.GLib.UnmappedError.GeoclueErrorQuark.Code1: Geoclue master client has no usable Address providers'
2015-03-10 19:13:50,541 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file
2015-03-10 19:13:50,542 - softwarecenter.plugin - INFO - activating plugin '<module 'webapps_activation' from '/usr/share/software-center/softwarecenter/plugins/webapps_activation.pyc'>'
2015-03-10 19:13:50,585 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open()
2015-03-10 19:13:51,024 - softwarecenter.backend.reviews - WARNING - error creating bsddb: '(22, 'Argomento non valido -- BDB0054 illegal flag combination specified to DB_ENV->open')' (corrupted?)
2015-03-10 19:13:51,025 - softwarecenter.backend.reviews - ERROR - trying to repair DB failed
Traceback (most recent call last):
  File "/usr/share/software-center/softwarecenter/backend/reviews/__init__.py", line 358, in _save_review_stats_cache_blocking
    self._dump_bsddbm_for_unity(outfile, outdir)
  File "/usr/share/software-center/softwarecenter/backend/reviews/__init__.py", line 377, in _dump_bsddbm_for_unity
    0600)
DBInvalidArgError: (22, 'Argomento non valido -- BDB0054 illegal flag combination specified to DB_ENV->open')
/usr/lib/python2.7/dist-packages/gi/overrides/GLib.py:535: Warning: Source ID 68 was not found when attempting to remove it
  return super(MainContext, self).iteration(may_block)
2015-03-10 19:13:52,031 - softwarecenter.ui.gtk3.views.lobbyview - WARNING - skipping exhibit for: 'u'leadwerks\r\nleadwerks-indie'' not available
/usr/bin/software-center:184: Warning: Source ID 135 was not found when attempting to remove it
  Gtk.main()
2015-03-10 19:13:57,331 - softwarecenter.region - WARNING - failed to use geoclue: 'org.freedesktop.DBus.GLib.UnmappedError.GeoclueErrorQuark.Code1: Geoclue master client has no usable Address providers'
/usr/lib/python2.7/dist-packages/gi/overrides/GLib.py:535: Warning: Source ID 20 was not found when attempting to remove it
  return super(MainContext, self).iteration(may_block)
2015-03-10 19:13:59,357 - softwarecenter.db.utils - INFO - software-center-agent finished with status 0

Qualcuno è in grado di aiutarmi? Grazie in anticipo!