We’ve had a lot of folks calling in recently about this one. The symptoms are that if you go to your calendar in Outlook and forward a meeting, the To field is prepopulated with all attendees of the meeting and the Subject field is not prefixed with “FW:.” The common denominator of all victims of this problem is that they all had their meetings processed with CDO 1.21. This is common if you are a Blackberry user, but could happen if any application processes your appointment with CDO 1.21 before you’ve had a chance to touch it with Outlook.
The real cause of the problem is that CDO 1.21 doesn’t clear the MSGFLAG_UNSENT flag from the PR_MESSAGE_FLAGS property when it does a Respond. Because this flag is still set on the appointment item in the calendar, Outlook (rightfully) thinks the message has not yet been sent and so it treats it like a new message – essentially.
I’ve requested a fix for this issue and it is currently being worked on by our development team. I’ll update this post if/when the fix becomes available.
[UPDATE| The fix is now available and accessible here: http://support.microsoft.com/default.aspx?scid=kb;EN-US;957020.