Open Stack

Hi,
with a recent openstack-grizzly installation (via packstack) I can successfully operate through the dashboard (load images into glance, launch/terminate image instances, etc.). 
The problem is with the nova command line tool which returns back an authorization problem:

nova --debug list
[...]
INFO (connectionpool:203) Starting new HTTP connection (1): 192.135.16.31
DEBUG (connectionpool:295) "GET /v2/2159cc8fafe244cfa7e3cad5c1f8a27f/servers/detail HTTP/1.1" 401 276
RESP: [401] {'date': 'Thu, 05 Sep 2013 14:25:53 GMT', 'content-length': '276', 'content-type': 'text/plain; charset=UTF-8', 'www-authenticate': "Keystone uri='http://192.135.16.31:35357'"}
RESP BODY: 401 Unauthorized

This server could not verify that you are authorized to access the document you requested. Either you supplied the wrong credentials (e.g., bad password), or your browser does not understand how to supply the credentials required.

 Authentication required  

DEBUG (shell:768) Unauthorized (HTTP 401)
Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/novaclient/shell.py", line 765, in main
    OpenStackComputeShell().main(map(strutils.safe_decode, sys.argv[1:]))
  File "/usr/lib/python2.6/site-packages/novaclient/shell.py", line 701, in main
    args.func(self.cs, args)
  File "/usr/lib/python2.6/site-packages/novaclient/v1_1/shell.py", line 937, in do_list
    servers = cs.servers.list(search_opts=search_opts)
  File "/usr/lib/python2.6/site-packages/novaclient/v1_1/servers.py", line 375, in list
    return self._list("/servers%s%s" % (detail, query_string), "servers")
  File "/usr/lib/python2.6/site-packages/novaclient/base.py", line 62, in _list
    _resp, body = self.api.client.get(url)
  File "/usr/lib/python2.6/site-packages/novaclient/client.py", line 230, in get
    return self._cs_request(url, 'GET', **kwargs)
  File "/usr/lib/python2.6/site-packages/novaclient/client.py", line 227, in _cs_request
    raise e
Unauthorized: Unauthorized (HTTP 401)
ERROR: Unauthorized (HTTP 401)

Of course I use the same (correct) credentials used with the dashboard (and downloaded from the dashboard itself: "Access & Security" -> "Download Openstack RC file").

Any idea about what should I look for to understand the cause of this error ?

thanks in advance,

	Alvise