Brad,
This comments area seems to have a limit. So, let me post my question in two parts.
- Part One -
Now, I have "restored" the self-assigned certificate to the CAS server that resides in a non-internet facing site. But the Outlook 2007 clients in that site starts to see security alert again, but a different one. "X The security certificate was issued by a company you have not chosen to trust..." This only happens after clicking the Scheduling Assistant to look up free/busy information of another user. And it only happens for the first time checking free/busy after Outlook 2007 is launched. Subsequent checking free/busy will not trigger such security alert. To reproduce the alert, I have to re-launch the Outlook client. I have tested this on two different computers. Both got the same issue. The interesting thing is answering Yes or No at the security alert does not seem to affect setting up and sending out the meeting request at all.
Adam