nondeterministic failure of allmydata.test.test_download.DownloadTest.test_lost_servers with NotEnoughSharesError

[davidsarah]

​http://tahoe-lafs.org/buildbot/builders/FreeStorm%20WinXP-x86%20py2.6/builds/273/steps/test/logs/stdio :

[ERROR]: allmydata.test.test_download.DownloadTest.test_lost_servers

Traceback (most recent call last):
Failure: allmydata.interfaces.NotEnoughSharesError: ran out of
shares: complete=sh4 pending=Share(sh7-on-k6vb2) overdue= unused=
need 3. Last failure: [Failure instance: Traceback (failure with no
frames): <class 'foolscap.tokens.RemoteException'>: <RemoteException
around '[Failure instance: Traceback: <class
'allmydata.test.no_network.IntentionalError'>: I was asked to break
c:\python26\lib\site-packages\twisted\internet\base.py:778:runUntilCurrent
build\bdist.win32\egg\foolscap\eventual.py:26:_turn
c:\python26\lib\site-packages\twisted\internet\defer.py:280:callback
c:\python26\lib\site-packages\twisted\internet\defer.py:354:_startRunCallbacks
--- <exception caught here> ---
c:\python26\lib\site-packages\twisted\internet\defer.py:371:_runCallbacks
c:\buildbot_tahoe\freestorm_winxp-x86_py2.6\build\src\allmydata\test\no_network.py:81:<lambda>
c:\buildbot_tahoe\freestorm_winxp-x86_py2.6\build\src\allmydata\test\no_network.py:68:_call
]'>
]

This test succeeds on other builders, and in the ​next build of the same source.