One issue might be that you are using the login/password of the openerp.com account. This will not work. You need to use the login/password of the database. In order to do so, you need to go to Settings>Users, then click on a user (that you will want to use through the API), then go to More>Change password, and make sure to specify a password there. You will then have to use this login/password in your API calls. Again, you have to realize that this is not the login/password of your openerp.com account.