"Parameter is invalid" error when signing C # VSTO manifest

I purchased from StartSSL ' Class Verification 2. ' Then I successfully generated an Object Code Signing (PFX) certificate and successfully imported my certificate into Visual Studio 2010.

Imported certificate in VS 2010 http://dl.dropbox.com/u/80507/signing/configuration.PNG

When I try to sign the VSTO manifest (to install PowerPoint Add-In ClickOnce) I get this error:

An error occured while signing: The parameter is incorrect.

      

        
        
        
      

    

Registration error http://dl.dropbox.com/u/80507/signing/error.PNG

I spoke with StartSSL and their certificate would have no problem with that.