WinMail Vista 64 can't see/use Personal Digital Certs

I'm having problems with Win Mail accessing any personal certs - instead it
wants to get digital id's and goes to the Office 2007 marketplace website
with IE. These certs were just issued by Thwate Freemail and according to IE
I've got the private keys, so there shouldn't be any problems with them.

I Do have Word/Excel/Powerpoint of Office 2007 Pro (Access and Outlook
available if needed), which could explain some of the Office 2007
Marketplace for Digital Certs issue but I'd like to get my new certs working
in Win Mail so any help is appreciated.