OL 2007 Is Not Saving Changes to Security Settings - "The messaging interface ha

I recently installed a new COMODO Digitial Certificate to replace one that expired. In Outlook 200 I go to Tools > Trust Center > E-mail Security and click on the Settings Button. Then in the Certificates and Algortithms section I have the opportunity to select a Signing Certificate and an Encryption Certificate. When I do that, only my new Digitial Certificate is provided as a pull-down option (which is fine, it means that I can’t choose an invalid one). When I select that Certificate the “Hash Algorithm” and “Encryption Algorithm” are automatically inserted. Everything works fine - I can send encrypted e-mail, etc. - until I exit Outlook and restart Outlook. When I do that the “Hash Algorithm” and “Encryption Algorithm” revert to blanks. If I try to send an encypted e-mail with those fields left blank I get an error message, “The messaging interface has returned an unknown error. If the problem persists, restart Outlook.” Restarting Outlook does not fix the problem. Going back and once again selecting my current Signing Certificate and an Encryption Certificate does fix the problem, but why is Outlook not saving these settings so that they are selected when I restart Outlook?


Someone at Microsoft Outlook’s Discussion Forum suggested to creating a new Outlook profile and check if that helps:
Create an Outlook profile - Microsoft Support

This is a pain in the neck because you have to import all of your old .pst info into the new profile, but it seems to have worked.