This can be duplicated with two users, UserA and UserB.
Steps to duplicate:
1) Login to UserA and give UserB read and write proxy rights for appointments
only. Make sure that minimum user access has no rights at all.
2) Login to UserB.
3) Proxy to UserA's Calendar and create a new posted appointment by
doubleclicking on the date of your choice.
4) Proxy back to userB and drag an Internet mail message (with userB being the
only recipient) from UserB's mailbox to the attachment field of the posted
5) Post the appointment.
6) Delete and empty (or archive) the Internet mail message from userB's
7) Proxy or login to UserA and try to open the appointment and notice the D107