password recovery cancel email problem

Hi - I having the following problem with the password recovery control.
As part of the requirements for the app I've developed, users are able to register without having to have an email address.
So my  password recovery control needs to be able to cancel the sent email if the the user does not have an email address and instead display the password in the browser. The control works okay if the user has an email but if they don't the following general failure message is displated - "Your attempt to retrieve your password was not successful. Please try again."

Below is my markup and code -
<asp:PasswordRecovery ID="PasswordRecovery1" runat="server" OnSendingMail="PasswordRecovery1_SendingMail"
            QuestionFailureText=&q ...