"The object could not be found"

[Don]

I have an unusual problem and am in need of some assistance. I have a user
who shares her managers calendar. She can see and open his appointments but
cannot make new ones. When she tries to open the timeslot on his calendar to
schedule a new appointment, she gets "The object could not be found". Her
permission on his side is publisher. Here's the ironic part, if I give myself
the same permissins, I can do it without any errors.

Suggestions??

Thanks - Don