Software Center dont show almost all technical itens

[Celso Henriques]

After a clean installation on ubuntu 12.04.1, ubuntu software center seems to don't find most of all hidden technical itens. Preload, gm-notify are just a few of them. I can only install them using apt-get comand on console. Even after install, software center can't find them.

the software-center comand on terminal shows this:

celso@Administrador:~$ software-center
2013-03-13 22:34:07,750 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None'
2013-03-13 22:34:07,755 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True
2013-03-13 22:34:07,756 - softwarecenter.db.database - ERROR - failed to add apt-xapian-index
Traceback (most recent call last):
  File "/usr/share/software-center/softwarecenter/db/database.py", line 183, in _get_new_xapiandb
    softwarecenter.paths.APT_XAPIAN_INDEX_DB_PATH)
  File "/usr/lib/python2.7/dist-packages/xapian/__init__.py", line 3666, in __init__
    _xapian.Database_swiginit(self,_xapian.new_Database(*args))
DatabaseOpeningError: Couldn't stat '/var/lib/apt-xapian-index/index' (Ficheiro ou directoria inexistente)
2013-03-13 22:34:08,142 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file
2013-03-13 22:34:08,284 - softwarecenter.ui.gtk3.app - INFO - show_available_packages: search_text is '', app is None.
2013-03-13 22:34:08,683 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open()
2013-03-13 22:34:13,192 - softwarecenter.db.categories - WARNING - sort by cataloged time requested but your a-x-i does not seem to support that yet
2013-03-13 22:34:14,010 - softwarecenter.db.categories - WARNING - sort by cataloged time requested but your a-x-i does not seem to support that yet
2013-03-13 22:34:14,111 - softwarecenter.db.categories - WARNING - sort by cataloged time requested but your a-x-i does not seem to support that yet
2013-03-13 22:34:14,168 - softwarecenter.db.categories - WARNING - sort by cataloged time requested but your a-x-i does not seem to support that yet
2013-03-13 22:34:14,223 - softwarecenter.db.categories - WARNING - sort by cataloged time requested but your a-x-i does not seem to support that yet
2013-03-13 22:34:14,925 - softwarecenter.db.categories - WARNING - sort by cataloged time requested but your a-x-i does not seem to support that yet
2013-03-13 22:34:14,978 - softwarecenter.db.categories - WARNING - sort by cataloged time requested but your a-x-i does not seem to support that yet
2013-03-13 22:34:17,254 - softwarecenter.db.update - INFO - skipping region restricted app: 'reEarCandy' (not whitelisted)
2013-03-13 22:34:17,436 - softwarecenter.db.update - INFO - skipping region restricted app: 'Bulleti d'esquerra de Calonge i Sant Antoni ' (not whitelisted)
2013-03-13 22:34:17,930 - softwarecenter.db.update - INFO - skipping region restricted app: 'Comentarios Web' (not whitelisted)
2013-03-13 22:34:19,301 - softwarecenter.ui.gtk3.app - INFO - software-center-agent finished with status 0
2013-03-13 22:34:19,302 - softwarecenter.db.database - INFO - reopen() database
2013-03-13 22:34:19,302 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True
2013-03-13 22:34:19,309 - softwarecenter.db.database - ERROR - failed to add apt-xapian-index
Traceback (most recent call last):
  File "/usr/share/software-center/softwarecenter/db/database.py", line 183, in _get_new_xapiandb
    softwarecenter.paths.APT_XAPIAN_INDEX_DB_PATH)
  File "/usr/lib/python2.7/dist-packages/xapian/__init__.py", line 3666, in __init__
    _xapian.Database_swiginit(self,_xapian.new_Database(*args))
DatabaseOpeningError: Couldn't stat '/var/lib/apt-xapian-index/index' (Ficheiro ou directoria inexistente)
2013-03-13 22:34:19,331 - softwarecenter.db.database - ERROR - failed to add apt-xapian-index
Traceback (most recent call last):
  File "/usr/share/software-center/softwarecenter/db/database.py", line 183, in _get_new_xapiandb
    softwarecenter.paths.APT_XAPIAN_INDEX_DB_PATH)
  File "/usr/lib/python2.7/dist-packages/xapian/__init__.py", line 3666, in __init__
    _xapian.Database_swiginit(self,_xapian.new_Database(*args))
DatabaseOpeningError: Couldn't stat '/var/lib/apt-xapian-index/index' (Ficheiro ou directoria inexistente)
No handlers could be found for logger "softwarecenter.db.database"

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: software-center 5.2.9
ProcVersionSignature: Ubuntu 3.2.0-38.61-generic 3.2.37
Uname: Linux 3.2.0-38-generic x86_64
ApportVersion: 2.0.1-0ubuntu17.1
Architecture: amd64
Date: Wed Mar 13 22:27:39 2013
InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120823.1)
MarkForUpload: True
PackageArchitecture: all
SourcePackage: software-center
UpgradeStatus: No upgrade log present (probably fresh install)