Signing Email with Internet Certificate "Bonus Feature"

I’m doing some work with signed and encrypted messages and have come across something that isn’t worling well for me.

I have an internet cert set up correctly (I assume) I can send signed messages and receive encrypted messages without problems… unless when sending a signed message, I use type ahead against a secondary address book to get the external contact’s name.

If I manually type in the persons internet address they get the message as a signed message. If I use type ahead, and their name is in the To field as a regular name (ie not an email address, upon sending I will get a message saying “Signing message”, just as I do when I use the internet address, however on the receiving side it doesn’t appear to be signed. I am assuming it is signing with the Notes cert…

If I go in the Advanced Detials for my internet certificate in the ID file through File, Security, User Security. The internet certificate that I have set up is selected as the default signing certificate.

Additionally I have set this cert up as the default for encryption in the person document within the Domino Directory.

Any suggestions?