I work for a city agency and we are having the same problem. There are
approximately 15 of us who are losing our shared calendars which includes
peoples calendars and other calendars. They are still in our favorites folder
but not in the shortcut as DR earlier stated.

"DR" wrote:

Diane Poremsky wrote:
When they disappear from favorites it usually means the profile is
corrupt or Outlook is not closing correctly, so the xml file holding the
data is not getting saved.

The best solution is a new profile - especially if you upgraded from an
earlier version.

If you use a PDA or other device or software that is accessing the
mailbox, disconnect or close it before closing outlook. This will allow
Outlook to close correctly and save the file.

Mine don't disappear from favorites, they stay there. But, they leave
the "Calendar" shortcut when I click on them.