The CAPI team that delivers the Microsoft Cryptography SDK (the unmanaged crypto API, not System.Security.Crytpography), will be having an online chat where they'll answer questions about using Crypto API.  They'll also take suggestions for changes to be made to the Cryptography SDK in the future.  The chat will be from 11:00am to noon Pacific Time (6:00pm-7:00pm GMT) on June 23rd.  You can access the chat here: http://communities2.microsoft.com/home/chatroom.aspx?siteid=34000014