remove-fixed-ip raise InvalidUUID Exception

1. use admin user to boot a instance
  hzgaott@114-113-199-x:~$ nova list
+--------------------------------------+----------------+---------+----------------------+
| ID | Name | Status | Networks |
+--------------------------------------+----------------+---------+----------------------+
| 6d74b0cc-5bb2-4233-b9a0-f80013412a3d | test-fixed-ip | ACTIVE | private=10.120.34.10 |

2. add additional fixed-ip to the instance
  hzgaott@114-113-199-x:~$ nova add-fixed-ip 6d74b0cc-5bb2-4233-b9a0-f80013412a3d f95c4d3b-44a1-436e-b6f5-d186569d9514
  hzgaott@114-113-199-x:~$ nova list
+--------------------------------------+----------------+---------+------------------------------------+
| ID | Name | Status | Networks |
+--------------------------------------+----------------+---------+------------------------------------+
| 6d74b0cc-5bb2-4233-b9a0-f80013412a3d | test-fixed-ip | ACTIVE | private=10.120.34.10, 10.120.34.18 |

3. remove the additional fixed-ip
    hzgaott@114-113-199-8:~$ nova remove-fixed-ip 6d74b0cc-5bb2-4233-b9a0-f80013412a3d 10.120.34.18
    return 202
    but the fixed-ip is still there.
    hzgaott@114-113-199-x:~$ nova list
+--------------------------------------+----------------+---------+------------------------------------+
| ID | Name | Status | Networks |
+--------------------------------------+----------------+---------+------------------------------------+
| 6d74b0cc-5bb2-4233-b9a0-f80013412a3d | test-fixed-ip | ACTIVE | private=10.120.34.10, 10.120.34.18 |

in nova-network.log
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp Traceback (most recent call last):
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp File "/usr/local/lib/python2.7/dist-packages/nova/openstack/common/rpc/amqp.py", line 275, in _process_data
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp rval = self.proxy.dispatch(ctxt, version, method, **args)
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp File "/usr/local/lib/python2.7/dist-packages/nova/openstack/common/rpc/dispatcher.py", line 145, in dispatch
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp return getattr(proxyobj, method)(ctxt, **kwargs)
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp File "/usr/local/lib/python2.7/dist-packages/nova/network/manager.py", line 257, in wrapped
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp return func(self, context, *args, **kwargs)
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp File "/usr/local/lib/python2.7/dist-packages/nova/network/manager.py", line 1217, in remove_fixed_ip_from_instance
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp fixed_ips = self.db.fixed_ip_get_by_instance(context, instance_id)
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp File "/usr/local/lib/python2.7/dist-packages/nova/db/api.py", line 482, in fixed_ip_get_by_instance
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp return IMPL.fixed_ip_get_by_instance(context, instance_uuid)
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp File "/usr/local/lib/python2.7/dist-packages/nova/db/sqlalchemy/api.py", line 129, in wrapper
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp return f(*args, **kwargs)
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp File "/usr/local/lib/python2.7/dist-packages/nova/db/sqlalchemy/api.py", line 1217, in fixed_ip_get_by_instance
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp raise exception.InvalidUUID(uuid=instance_uuid)
2012-10-12 16:50:20 TRACE nova.openstack.common.rpc.amqp InvalidUUID: Expected a uuid but received 559.

the method "fixed_ip_get_by_instance" in sqlalchemy/api.py used instance uuid rather than id, so change id to uuid in network/api.py can fix the bug.