Please see the following post for a similar resolved issue:
http://community.auth0.com/questions/3944/error-grant-type-password-not-allowed-for-the-clie
It includes details on why this happens and how you can work around it
Please see the following post for a similar resolved issue:
http://community.auth0.com/questions/3944/error-grant-type-password-not-allowed-for-the-clie
It includes details on why this happens and how you can work around it