CRM 2011 SDK error: An unsecured or incorrectly secured fault was received from the other party. See the inner FaultException for the fault code and detail.

To resolve this error:
Go to C:\Users\[Login User ID]\LiveDeviceID folder and delete the LiveDevice.xml file.

Reference: http://crmconsultancy.wordpress.com/2010/10/25/plugins-in-crm-2011/