Unhandled Exception for Shared Calendar

[silvrwood]

User B has Editor permissions to User A's calendar. About once a day when
User B tries to enter the calendar portion of her Outlook, it crashes with an
Unhandled Exception: Description - EXCEPTION_ACCESS_VIOLATION. The only
thing that allows her to work within her calendar is for me to remove User A
from her additional mailboxes, restart the system, start Outlook & readd User
A as an additional mailbox.
I have added his mailbox for my account as well and tested to see if my
program crashes when hers does. It does not.
I have repaired Outlook & installed all security & Win updates. This still
happens.

Any ideas?