Take a look at this MS KB article, it may help:
http://support.microsoft.com/default...;en-us;Q238976
"Barbara" <(E-Mail Removed)> wrote in message
news:85BC12D0-A710-46EF-9514-(E-Mail Removed)...
>I have user and when she created an appt it automatically set it as
>private.
> I resolved this by using the new design form but the problem stil occurs
> if
> she creates an appointment in another usesr calendar that she has access
> too?
> When I do a properties on the calendar the option to change "when
> posting
> to this folder, use" is greyed out so I can't select the newly created
> form.