Failed to terminate/reboot instane (LXC)

Hi,

When I want to terminate or reboot some LXC instances, I have the following error:

2012-03-28 20:23:55 WARNING nova.virt.libvirt.connection [-] [instance: 5051d58e-7e08-43b7-8bfd-24c1f04de5ae] Error from libvirt during destroy. Code=1 Error=internal error Some container PIDs refused to die
2012-03-28 20:23:55 ERROR nova.rpc.common [-] Exception during message handling
(nova.rpc.common): TRACE: Traceback (most recent call last):
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/dist-packages/nova/rpc/amqp.py", line 250, in _process_data
(nova.rpc.common): TRACE: rval = node_func(context=ctxt, **node_args)
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/dist-packages/nova/exception.py", line 112, in wrapped
(nova.rpc.common): TRACE: return f(*args, **kw)
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 156, in decorated_function
(nova.rpc.common): TRACE: function(self, context, instance_uuid, *args, **kwargs)
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 180, in decorated_function
(nova.rpc.common): TRACE: sys.exc_info())
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/contextlib.py", line 24, in __exit__
(nova.rpc.common): TRACE: self.gen.next()
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 174, in decorated_function
(nova.rpc.common): TRACE: return function(self, context, instance_uuid, *args, **kwargs)
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 736, in terminate_instance
(nova.rpc.common): TRACE: self._delete_instance(context, instance)
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 716, in _delete_instance
(nova.rpc.common): TRACE: self._shutdown_instance(context, instance, 'Terminating')
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 687, in _shutdown_instance
(nova.rpc.common): TRACE: block_device_info)
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/connection.py", line 425, in destroy
(nova.rpc.common): TRACE: cleanup=True)
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/connection.py", line 351, in _destroy
(nova.rpc.common): TRACE: virt_dom.destroy()
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/dist-packages/libvirt.py", line 560, in destroy
(nova.rpc.common): TRACE: if ret == -1: raise libvirtError ('virDomainDestroy() failed', dom=self)
(nova.rpc.common): TRACE: libvirtError: internal error Some container PIDs refused to die
(nova.rpc.common): TRACE:

Best regards.
Sam