I am having a problem with Outlook Calendars.

One of our users has a recurring meeting every week. She made a change
to it for this week and this is the problem:

The recurring meeting is Tuesdays from 9-10. User 1 changed the 7/17
meeting to Wednesday, 7/18, from 11:30-1:30 and It was accepted by
user 2. The Tuesday meeting disappeared (as it should) from user 1's
Outlook calendar ... BUT it still appears on her Blackberry and,
bizarrely, it still appears on user 2's calendar in the original time
slot. When user 1's assistant opens user 1's calendar the meeting is
also still in the original time slot and has not changed. The
assistant also printed user 1's daily calendar and it appears on it in
the original time slot. This also isnt the first time it has happened,
she said this has happened before.

Has anyone run into this issue before? any help would be
appreciated. Thanks.