Multiple Recipients, S/MIME, Outlook, and Entourage 2004

[SMFX]

I trying to narrow this down and not having a whole lot of luck. I have an Exchange environment with Outlook and Entourage clients. We have issued certificates and keys to all clients to sign & encrypt e-mails.

It works fine for:
* Outlook 2003 to Entourage 2004 single recipient, and reverse
* Outlook 2003 to Outlook 2003 multiple recipients
* Entourage 2004 to Outlook 2003 multiple recipients
* Entourage 2004 to Entourage 2004 multiple recipients

It has issues with:
* Outlook 2003 to Entourage 2004 with multiple recipients

When I say issue, if you address the message to more than one user and one of those users is on Entourage 2004, the Entourage 2004 users will only see an attachment "smime.p7m".

Does anyone have any ideas?

Thank you,
-SMFX