test_routers fails with: TearDownException: %(num)d cleanUp operation failed

http://logs.openstack.org/57/55557/3/check/check-tempest-devstack-vm-neutron/16876f9/console.html

2013-11-21 11:06:52.407 | ======================================================================
2013-11-21 11:06:52.407 | FAIL: tearDownClass (tempest.api.network.test_routers.RoutersTest)
2013-11-21 11:06:52.407 | tearDownClass (tempest.api.network.test_routers.RoutersTest)
2013-11-21 11:06:52.408 | ----------------------------------------------------------------------
2013-11-21 11:06:52.408 | _StringException: Traceback (most recent call last):
2013-11-21 11:06:52.409 | File "tempest/api/network/base.py", line 139, in tearDownClass
2013-11-21 11:06:52.410 | raise exceptions.TearDownException()
2013-11-21 11:06:52.410 | TearDownException: %(num)d cleanUp operation failed

I see this in the neutron-server log:

http://logs.openstack.org/57/55557/3/check/check-tempest-devstack-vm-neutron/16876f9/logs/screen-q-svc.txt.gz

2013-11-21 11:05:09.802 2485 ERROR neutron.api.v2.resource [-] show failed
2013-11-21 11:05:09.802 2485 TRACE neutron.api.v2.resource Traceback (most recent call last):
2013-11-21 11:05:09.802 2485 TRACE neutron.api.v2.resource File "/opt/stack/new/neutron/neutron/api/v2/resource.py", line 84, in resource
2013-11-21 11:05:09.802 2485 TRACE neutron.api.v2.resource result = method(request=request, **args)
2013-11-21 11:05:09.802 2485 TRACE neutron.api.v2.resource File "/opt/stack/new/neutron/neutron/api/v2/base.py", line 290, in show
2013-11-21 11:05:09.802 2485 TRACE neutron.api.v2.resource parent_id=parent_id),
2013-11-21 11:05:09.802 2485 TRACE neutron.api.v2.resource File "/opt/stack/new/neutron/neutron/api/v2/base.py", line 258, in _item
2013-11-21 11:05:09.802 2485 TRACE neutron.api.v2.resource obj = obj_getter(request.context, id, **kwargs)
2013-11-21 11:05:09.802 2485 TRACE neutron.api.v2.resource File "/opt/stack/new/neutron/neutron/db/l3_db.py", line 687, in get_floatingip
2013-11-21 11:05:09.802 2485 TRACE neutron.api.v2.resource floatingip = self._get_floatingip(context, id)
2013-11-21 11:05:09.802 2485 TRACE neutron.api.v2.resource File "/opt/stack/new/neutron/neutron/db/l3_db.py", line 449, in _get_floatingip
2013-11-21 11:05:09.802 2485 TRACE neutron.api.v2.resource raise l3.FloatingIPNotFound(floatingip_id=id)
2013-11-21 11:05:09.802 2485 TRACE neutron.api.v2.resource FloatingIPNotFound: Floating IP 1155c656-d0e8-49c2-b30f-8a98e5bd1ed7 could not be found
2013-11-21 11:05:09.802 2485 TRACE neutron.api.v2.resource