fails to show previous purchases; traceback in parent shell instead

The scrollback from my shell contains this:

[-(Thu 2011-05-19 6:08:38)-(~/)-]> software-center (selene @ GiR)
2011-05-19 06:08:44,383 - softwarecenter.fixme - WARNING - logs to the root logger: '('/usr/share/software-center/softwarecenter/view/widgets/mkit_themes.py', 675, 'retrieve')'
2011-05-19 06:08:44,383 - root - WARNING - No styling hints for Raleigh were found... using Human hints.
/usr/share/software-center/softwarecenter/app.py:1192: Warning: g_object_set_qdata: assertion `G_IS_OBJECT (object)' failed
  self.window_main.show_all()
2011-05-19 06:08:44,855 - softwarecenter.fixme - WARNING - logs to the root logger: '('/usr/lib/pymodules/python2.7/zeitgeist/client.py', 367, 'reconnect_monitors')'
2011-05-19 06:08:44,855 - zeitgeist.client - INFO - Reconnected to Zeitgeist engine...
/usr/share/software-center/softwarecenter/SimpleGtkbuilderApp.py:50: Warning: g_object_set_qdata: assertion `G_IS_OBJECT (object)' failed
  gtk.main()
2011-05-19 06:08:47,308 - softwarecenter.app - INFO - software-center-agent finished with status 1

# about to click file -> reinstall previous purchases:

2011-05-19 06:09:16,699 - softwarecenter.fixme - WARNING - logs to the root logger: '('/usr/share/software-center/softwarecenter/backend/restfulclient.py', 254, '_thread_available_for_me_error')'
2011-05-19 06:09:16,699 - root - ERROR - _available_for_me_error HTTP Error 500: INTERNAL SERVER ERROR
Response headers:
---
cache-control: max-age=0
connection: close
content-type: text/html; charset=utf-8
date: Thu, 19 May 2011 12:09:16 GMT
etag: "b34cd71bab7cc3596a0b5086d8471c0f"
expires: Thu, 19 May 2011 12:09:16 GMT
last-modified: Thu, 19 May 2011 12:09:16 GMT
server: Apache/2.2.14 (Ubuntu)
status: 500
transfer-encoding: chunked
vary: Authorization,Cookie,Accept-Encoding
via: 1.1 software-center.ubuntu.com
---
Response body:
---
Piston/0.2.2 (Django 1.1.1) crash report:

Traceback (most recent call last):

  File "/usr/lib/python2.6/dist-packages/softwarecenteragent/api10/handlers.py", line 62, in read
    return self.named_operation(request, request.GET)

  File "/usr/lib/python2.6/dist-packages/softwarecenteragent/api10/handlers.py", line 77, in named_operation
    return method(request)

  File "/usr/lib/python2.6/dist-packages/softwarecenteragent/api10/handlers.py", line 177, in getForOAuthToken
    if web_services.verify_identity(oauth_token, openid_identifier):

  File "/usr/lib/python2.6/dist-packages/softwarecenteragent/utilities.py", line 126, in verify_identity
    token=token, consumer_key=openid_identifier)

  File "/usr/lib/pymodules/python2.6/lazr/restfulclient/resource.py", line 527, in __call__
    url, in_representation, http_method, extra_headers=extra_headers)

  File "/usr/lib/pymodules/python2.6/lazr/restfulclient/_browser.py", line 306, in _request
    raise HTTPError(response, content)

HTTPError: HTTP Error 400: Bad Request
Response headers:
---
connection: close
content-length: 33
content-type: text/plain
date: Thu, 19 May 2011 12:09:16 GMT
server: Apache/2.2.14 (Ubuntu)
status: 400
vary: Accept-Encoding
via: 1.1 login.ubuntu.com
x-powered-by: Zope (www.zope.org), Python (www.python.org)
---
Response body:
---
token: Requ...

same here.
logging out of ubuntu one and deleting all saved passwords from keyring forced new login in software center but did not fix the problem.

Hi Selene, thanks for the report and for the excellent (annoted!) traceback. This issue has already been reported in bug 783896 so I will mark this as a duplicate of that one. I've already copied your traceback over to there. Thanks again!