test_txwebclient.WebClientShutdownTestCase.test_shutdown fails on windows

Trace is:

===============================================================================
[ERROR]
Traceback (most recent call last):
Failure: twisted.trial.util.DirtyReactorAggregateError: Reactor was unclean.
DelayedCalls: (set twisted.internet.base.DelayedCall.debug = True to debug)
<DelayedCall 0x744a8f0 [29.0020000935s] called=0 cancelled=0 Client.failIfNotConnected(TimeoutErr
or('',))>

ubuntuone.controlpanel.web_client.tests.test_txwebclient.WebClientShutdownTestCase.test_shutdown
===============================================================================
[ERROR]
Traceback (most recent call last):
Failure: twisted.trial.util.DirtyReactorAggregateError: Reactor was unclean.
Selectables:
<<class 'twisted.internet.tcp.Client'> to ('localhost', 52302) at 7436130>

ubuntuone.controlpanel.web_client.tests.test_txwebclient.WebClientShutdownTestCase.test_shutdown