Hi -

Are you already running Exchange 2003 SP2 with Unity 4.0(4)? This version is a requirement for the KB911829. If you are not running Exchange 2003 SP2 yet, please read this article - http://www.cisco.com/en/US/customer/products/sw/voicesw/ps2237/products_field_notice09186a00807dcf40.shtml

You will need to adjust your Send As permissions. There was also a new permissions wizard version that was needed for Exchange 2003 SP1 to maintain voice message functionality - http://www.cisco.com/en/US/customer/products/sw/voicesw/ps2237/products_field_notice09186a008024d72f.shtml

Also, Cisco now has its own process for applying security or other hotfixes to its applicable voice servers, which include Unity. Here is the new link - http://www.cisco.com/en/US/docs/voice_ip_comm/unity/updates/wizard/cuupwz.html

I did not see KB911829 in the list, so you might want to check with TAC on this. In any case, I would recommend breaking your Unity server's mirror set and ensuring you have a good backup for recovery before applying any update to your server.

Hope this helps! Ginger