integer imageRef causes HTTP 500

(nova.api.openstack): TRACE: Traceback (most recent call last):
(nova.api.openstack): TRACE: File "/usr/lib/python2.6/dist-packages/nova/api/openstack/__init__.py", line 41, in __call__
(nova.api.openstack): TRACE: return req.get_response(self.application)
(nova.api.openstack): TRACE: File "/usr/lib/pymodules/python2.6/webob/request.py", line 919, in get_response
(nova.api.openstack): TRACE: application, catch_exc_info=False)
(nova.api.openstack): TRACE: File "/usr/lib/pymodules/python2.6/webob/request.py", line 887, in call_application
(nova.api.openstack): TRACE: app_iter = application(self.environ, start_response)
(nova.api.openstack): TRACE: File "/usr/lib/pymodules/python2.6/webob/dec.py", line 159, in __call__
(nova.api.openstack): TRACE: return resp(environ, start_response)
(nova.api.openstack): TRACE: File "/usr/lib/pymodules/python2.6/webob/dec.py", line 159, in __call__
(nova.api.openstack): TRACE: return resp(environ, start_response)
(nova.api.openstack): TRACE: File "/usr/lib/pymodules/python2.6/routes/middleware.py", line 131, in __call__
(nova.api.openstack): TRACE: response = self.app(environ, start_response)
(nova.api.openstack): TRACE: File "/usr/lib/pymodules/python2.6/webob/dec.py", line 159, in __call__
(nova.api.openstack): TRACE: return resp(environ, start_response)
(nova.api.openstack): TRACE: File "/usr/lib/pymodules/python2.6/webob/dec.py", line 147, in __call__
(nova.api.openstack): TRACE: resp = self.call_func(req, *args, **self.kwargs)
(nova.api.openstack): TRACE: File "/usr/lib/pymodules/python2.6/webob/dec.py", line 208, in call_func
(nova.api.openstack): TRACE: return self.func(req, *args, **kwargs)
(nova.api.openstack): TRACE: File "/usr/lib/python2.6/dist-packages/nova/api/openstack/wsgi.py", line 786, in __call__
(nova.api.openstack): TRACE: content_type, body, accept)
(nova.api.openstack): TRACE: File "/usr/lib/python2.6/dist-packages/nova/api/openstack/wsgi.py", line 834, in _process_stack
(nova.api.openstack): TRACE: action_result = self.dispatch(meth, request, action_args)
(nova.api.openstack): TRACE: File "/usr/lib/python2.6/dist-packages/nova/api/openstack/wsgi.py", line 908, in dispatch
(nova.api.openstack): TRACE: return method(req=request, **action_args)
(nova.api.openstack): TRACE: File "/usr/lib/python2.6/dist-packages/nova/api/openstack/compute/servers.py", line 650, in create
(nova.api.openstack): TRACE: image_href = image_href.split('/').pop()
(nova.api.openstack): TRACE: AttributeError: 'int' object has no attribute 'split'
(nova.api.openstack): TRACE: