OpenStack API Requiring X-Auth-User on all requests

After authenticating with the OpenStack API, subsequent requests to nova should only require the X-Auth-Token for authentication. However, it also requires the X-Auth-User header to be present; it doesn't matter what the user value is.

Here is the stack trace for a request with only X-Auth-Token:

Traceback (most recent call last):
  File "/usr/local/lib/python2.6/dist-packages/eventlet/wsgi.py", line 336, in handle_one_response
    result = self.application(self.environ, start_response)
  File "/usr/local/lib/python2.6/dist-packages/webob/dec.py", line 159, in __call__
    return resp(environ, start_response)
  File "/usr/local/lib/python2.6/dist-packages/routes/middleware.py", line 131, in __call__
    response = self.app(environ, start_response)
  File "/usr/local/lib/python2.6/dist-packages/webob/dec.py", line 159, in __call__
    return resp(environ, start_response)
  File "/usr/local/lib/python2.6/dist-packages/webob/dec.py", line 159, in __call__
    return resp(environ, start_response)
  File "/usr/local/lib/python2.6/dist-packages/webob/dec.py", line 159, in __call__
    return resp(environ, start_response)
  File "/usr/local/lib/python2.6/dist-packages/webob/dec.py", line 147, in __call__
    resp = self.call_func(req, *args, **self.kwargs)
  File "/usr/local/lib/python2.6/dist-packages/webob/dec.py", line 208, in call_func
    return self.func(req, *args, **kwargs)
  File "/root/novascript/nova/nova/api/openstack/__init__.py", line 109, in __call__
    username = req.headers['X-Auth-User']
  File "/usr/local/lib/python2.6/dist-packages/webob/datastruct.py", line 40, in __getitem__
    return self.environ[self._trans_name(item)]
KeyError: 'HTTP_X_AUTH_USER'