Some recurring calendar items disappear from the "Day/Week/Month" view in Outlook when a user uses Exchange ActiveSync on a mobile device to modify a recurring meeting in an Exchange 2003 environment: http://support.microsoft.com/default.aspx?scid=kb;en-us;958781In a Microsoft Exchange 2003 environment, when a user uses Microsoft Exchange ActiveSync on a mobile device to modify a recurring meeting, some recurring calendar items disappear from the "Day/Week/Month" view in Outlook. However, they can still be seen in the "By Category" view. If you try to open the calendar items in the "By Category" view, you receive the following error message: