I'm attempting to use Live Mail 2012 to send encrypted / digitally signed emails in order to evaluate it as a means of securing communications between members of my startup company.  I have a digital certificate in .cer format that I've attempted to import through the Security tab of the Safety Options dialog.  When I select the .cer and add it to the Personal store, I receive a message, "The import was successful."  However, the certificate does not show up in the certificates list, and when I attempt to send any signed or encrypted emails, I'm told I must "first obtain a digital ID for this account." 

Any ideas why Live Mail is telling me the import is successful, when it clearly isn't?  Is there any trick to getting a cert imported?