This is from KB13149 ("Unable to synchronize calendar with duplicate entries from a BlackBerry Internet Service integration").

Of particular interest is the Workaround offered at the bottom of the post.

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Problem

The presence of multiple BlackBerry Internet Service [CICAL] service books can lead to duplicate calendar entries if an appointment in the non-default calendar is modified. These duplicate calendar entries will prevent a wired synchronization with BlackBerry Desktop Manager.

Cause

Cause 1

The first BlackBerry Internet Service [CICAL] service book sent inherits the appointments from the base system calendar (calendar appointments which were created before any calendar service books were sent to the BlackBerry smartphone). The last BlackBerry Internet Service [CICAL] service book sent to the BlackBerry smartphone is the default calendar.

Note:

* This issue does not affect BlackBerry smartphone users that are associated with a BlackBerry Enterprise Server or only have one email account integrated with the BlackBerry Internet Service.
* Appointments created before the last BlackBerry Internet Service [CICAL] service book was sent will be affected.
* New appointments created after the last BlackBerry Internet Service [CICAL] service book is sent, will not be affected and will work as expected.

Cause 2

If the duplicate message says received using unknown, the duplicate was sent using BlackBerry® Desktop Redirector.


Resolution

Cause 1

The first BlackBerry Internet Service [CICAL] service book sent inherits the appointments from the base system calendar (calendar appointments which were created before any calendar service books were sent to the BlackBerry smartphone).

Resolution 1

If you are running BlackBerry Device Software 4.2.2.66 to 4.2.2.103, install the 2007 Calendar Patch. For instructions, see 2007 Calendar Patch for BlackBerry Smartphones.

Note: To identify which BlackBerry Device Software version you have installed on your BlackBerry smartphone, go to the Home screen and select Options > About.

Resolution 2

Upgrade to BlackBerry Device Software 4.2.2 or later. For instructions, see KB03621.

Note: Verify that the version of BlackBerry Device Software contains Applications 4.2.2.114 or later. To identify which BlackBerry Device Software version you have installed on your BlackBerry smartphone, go to the Home screen and select Options > About.

Cause 2

If the duplicate message says received using unknown, the duplicate was sent using BlackBerry Desktop Redirector.

Resolution 1

Reinstall BlackBerry Desktop Manager for the BlackBerry Internet Service rather than BlackBerry Desktop Redirector for BlackBerry Enterprise Server.


Workaround

Clear and restore the calendar data on the BlackBerry smartphone.

1. Using BlackBerry Desktop Manager, back up the BlackBerry smartphone calendar data. For instructions, see KB11297.
2. Using BlackBerry Desktop Manager clear the BlackBerry smartphone calendar database. For instructions, see KB05340.
3. Manually delete all but one BlackBerry Internet Service [CICAL] service books, by completing the following steps:
* On the BlackBerry smartphone, go to Options > Advanced Options > Service Book.
* Delete all but one BlackBerry Internet Service [CICAL] service books. Eeach integration will have an integration named service book, such as <BlackBerry Internet Service integration_name>[CICAL].
4. Perform a hard reset of the BlackBerry smartphone. For instructions, see KB02141.
5. Restore the calendar data to the BlackBerry smartphone. For instructions, see KB10339.

Important: Should another BlackBerry Internet Service [CICAL] service book be sent to the BlackBerry smartphone, this workaround will need to be repeated in order to move the appointments to the newly sent calendar service.

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