suMicrosoft Outlook 2007 Encryption

Hi,

I'm running Windows XP with all SP's and necessary updates on an IBM
T400 with 2GB of memory and a 2.26GHz Duo CPU. I periodically need to
send/receive encrypted email. I am using a DoD issued CAC with correct
pub/pri keys. I'm using ActivClient 6.1 as my CAC software. When I
receive an encrypted email and attempt to open, Outlook nearly
crashes. When I open Task Mgr I can see CPU/Mem usuage skyrocket.
Today it went from about 40mb of memory to over 400mb in less than a
minute. CPU util jumps up and down. I've read several blogs and just
got done archiving about a 1000 emails but can't find anything
pertaining to email encryption issues. I now have less than 100 and it
still is a problem. Outlook seems to run fine when I don't digitally
sign/encrypt email. Any suggestions?

Jason