I looked at many other questions but none of them helped me. It closes immediately after I open it. When I opened it it Terminal I got this...
2013-03-15 17:20:07,156 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None'
2013-03-15 17:20:07,160 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True
2013-03-15 17:20:07,440 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file
2013-03-15 17:20:07,447 - softwarecenter.fixme - WARNING - logs to the root logger: '('/usr/lib/python2.7/dist-packages/gi/importer.py', 51, 'find_module')'
2013-03-15 17:20:07,446 - root - ERROR - Could not find any typelib for LaunchpadIntegration
2013-03-15 17:20:07,518 - softwarecenter.ui.gtk3.app - INFO - show_available_packages: search_text is '', app is None.
Bus error (core dumped)