i have a user who has been experiencing similar issues (and wouldnt you know
it, shes the admin who supports all of our company execs...). i have run
every switch that i can think of, even went so far as to delete and recreate
her local machine profile but have not been able to fix it (she does not have
the same problem when she logs onto a different machine). my user's issue is
intermittent, too. she may be able to open up calendars from her delegators
in the morning, but mid morning and into the afternoon, she will have
difficulty opening a delegator's calendar so that she has to close down
outlook, sometimes even reboot, and open it again.

if MS has seen this behavior and knows it to be an issue, i'd like to hear
about it...