nova-compute startup error

2011-11-08 11:54:33,290 CRITICAL nova [-] (406, u"PRECONDITION_FAILED - cannot redeclare exchange 'compute_fanout' in vhost '/' with different type, durable or autodelete value", (40, 10), 'Channel.exchange_declare')
(nova): TRACE: Traceback (most recent call last):
(nova): TRACE:   File "/home/rohit/nova/bin/nova-compute", line 49, in <module>
(nova): TRACE:     service.wait()
(nova): TRACE:   File "/home/rohit/nova/nova/service.py", line 385, in wait
(nova): TRACE:     _launcher.wait()
(nova): TRACE:   File "/home/rohit/nova/nova/service.py", line 111, in wait
(nova): TRACE:     service.wait()
(nova): TRACE:   File "/usr/lib/python2.6/dist-packages/eventlet/greenthread.py", line 166, in wait
(nova): TRACE:     return self._exit_event.wait()
(nova): TRACE:   File "/usr/lib/python2.6/dist-packages/eventlet/event.py", line 116, in wait
(nova): TRACE:     return hubs.get_hub().switch()
(nova): TRACE:   File "/usr/lib/python2.6/dist-packages/eventlet/hubs/hub.py", line 177, in switch
(nova): TRACE:     return self.greenlet.switch()
(nova): TRACE:   File "/usr/lib/python2.6/dist-packages/eventlet/greenthread.py", line 192, in main
(nova): TRACE:     result = function(*args, **kwargs)
(nova): TRACE:   File "/home/rohit/nova/nova/service.py", line 81, in run_server
(nova): TRACE:     server.start()
(nova): TRACE:   File "/home/rohit/nova/nova/service.py", line 165, in start
(nova): TRACE:     self.conn.create_consumer(self.topic, self, fanout=True)
(nova): TRACE:   File "/home/rohit/nova/nova/rpc/impl_kombu.py", line 494, in create_consumer
(nova): TRACE:     self.declare_fanout_consumer(topic, ProxyCallback(proxy))
(nova): TRACE:   File "/home/rohit/nova/nova/rpc/impl_kombu.py", line 457, in declare_fanout_consumer
(nova): TRACE:     self.declare_consumer(FanoutConsumer, topic, callback)
(nova): TRACE:   File "/home/rohit/nova/nova/rpc/impl_kombu.py", line 394, in declare_consumer
(nova): TRACE:     self.consumer_num.next())
(nova): TRACE:   File "/home/rohit/nova/nova/rpc/impl_kombu.py", line 210, in __init__
(nova): TRACE:     **options)
(nova): TRACE:   File "/home/rohit/nova/nova/rpc/impl_kombu.py", line 61, in __init__
(nova): TRACE:     self.reconnect(channel)
(nova): TRACE:   File "/home/rohit/nova/nova/rpc/impl_kombu.py", line 68, in reconnect
(nova): TRACE:     self.queue.declare()
(nova): TRACE:   File "/usr/local/lib/python2.6/dist-packages/kombu/entity.py", line 380, in declare
(nova): TRACE:     self.exchange.declare(nowait)
(nova): TRACE:   File "/usr/local/lib/python2.6/dist-packages/kombu/entity.py", line 154, in declare
(nova): TRACE:     nowait=nowait)
(nova): TRACE:   File "/usr/local/lib/python2.6/dist-packages/kombu/syn.py", line 23, in blocking
(nova): TRACE:     return __sync_current(fun, *args, **kwargs)
(nova): TRACE:   File "/usr/local/lib/python2.6/dist-packages/kombu/syn.py", line 49, in __eblocking__
(nova): TRACE:     return spawn(fun, *args, **kwargs).wait()
(nova): TRACE:   File "/usr/lib/python2.6/dist-packages/eventlet/greenthread.py", line 166, in wait
(nova): TRACE:     return self._exit_event.wait()
(nova): TRACE:   File "/usr/lib/python2.6/dist-packages/eventlet/event.py", line 116, in wait
(nova): TRACE:     return hubs.get_hub().switch()
(nova): TRACE:   File "/usr/lib/python2.6/dist-packages/eventlet/hubs/hub.py", line 177, in switch
(nova): TRACE:     return self.greenlet.switch()
(nova): TRACE:   File "/usr/lib/python2.6/dist-packages/eventlet/greenthread.py", line 192, in main
(nova): TRACE:     result = function(*args, **kwargs)
(nova): TRACE:   File "/usr/local/lib/python2.6/dist-packages/amqplib/client_0_8/channel.py", line 843, in exchange_declare
(nova): TRACE:     (40, 11),    # Channel.exchange_declare_ok
(nova): TRACE:   File "/usr/local/lib/python2.6/dist-packages/amqplib/client_0_8/abstract_channel.py", line 97, in wait
(nova): TRACE:     return self.dispatch_method(method_sig, args, content)
(nova): TRACE:   File "/usr/local/lib/python2.6/dist-packages/amqplib/client_0_8/abstract_channel.py", line 115, in dispatch_method
(nova): TRACE:     return amqp_method(self, args)
(nova): TRACE:   File "/usr/local/lib/python2.6/dist-packages/amqplib/client_0_8/channel.py", line 273, in _close
(nova): TRACE:     (class_id, method_id))
(nova): TRACE: AMQPChannelException: (406, u"PRECONDITION_FAILED - cannot redeclare exchange 'compute_fanout' in vhost '/' with different type, durable or autodelete value", (40, 10), 'Channel.exchange_declare')
(nova): TRACE: