the following scenario. As a delegate in
Microsoft Exchange Server 2007 environment, you create, send,
and then update meeting requests
for the organizer by using Exchange Web Service (EWS). However, the
operation does not work if the delegate tries to cancel a meeting,
tries to send the cancellation update
for the organizer by using EWS. In
this scenario, when the delegate tries to cancel a
meeting for the organizer, an "ErrorItemNotFound"
To resolve this problem, install the following update rollup:
Description of Update Rollup 1 for Exchange Server 2007 Service Pack 2
has confirmed that this is a problem in the Microsoft products that are listed
in the "Applies to" section.