Contacts are duplicated on the BlackBerry smartphone after wireless synchronization

Cause

When synchronized over the wireless network, the contact list and its subfolders in Microsoft Outlook appear in one folder on the BlackBerry smartphone. Therefore, if a contact list is found in more than one subfolder in Microsoft Outlook, it is duplicated on the BlackBerry smartphone.

Resolution

To prevent a duplicate contact list from appearing in the BlackBerry smartphone contact list, complete the following tasks;

Task 1

Move the subfolders
In Microsoft Outlook, move any subfolders from the Contacts folder to the Mailbox folder or the Inbox folder.

1. Right-click the subfolder and select Move<Folder Name>.
2. In the Move Folder window, select the desired folder to move the subfolder to (either Mailbox –<Username> orInbox).

Task 2

Disable Wireless Synchronization

1. On the BlackBerry smartphone Home screen, click Contacts.
2. In the contact list, press the Menu key and click Options.
3. On the Contacts Options screen, next to Wireless Synchronization, click Yes and change it to No.
4. Press the Escape key and select Save.      

Task 3

Clear the contact list from the BlackBerry smartphone

1. Connect the BlackBerry smartphone to the computer and open the BlackBerry Desktop Manager.
2. Click Backup and Restore.
3. Click Advanced. The BlackBerry smartphone application databases appear in the right pane.
4. From the right pane, select the Address book All database.
5. Click the arrow to transfer the database to the left pane. This also saves a backup copy of the database on the computer.
6. When a copy of the database appears in the left pane, select the address book database on the right side, and click Clear.
7. Click Close and select Yes when prompted to save the backup database file to the computer.

Task 4

Enable Wireless Synchronization

1. On the BlackBerry smartphone Home screen, click Contacts.
• In the contact list, press the Menu key and select Options.
• On the Contact Options screen, next to Wireless Synchronization, click No and change it to Yes.
• Press the Escape key and select Save.       

Duplicate Contacts on Blackberry Using Blackberry Enterprise/Professional

If a Blackberry isn't wiped out prior to configuring it for use on Blackberry Enterprise Services, then duplicate contact can appear, causing a frustrating need to delete the unwanted entries one by one.  Sometimes this can also occur if a user attempts to synchronize from the Blackberry Desktop Manager on their computer.  Two "Desktop" contact lists are shown on the device and one of them is configured for wireless synchronization.  You can't clear out an address book database on a BE blackberry because it's marked as read-only -- what do you do?
Solution 1
1. You reset the address book from the device, which completely clears the address book and repopulates it based on the Blackberry Enterprise Server information:

1.  On the Blackberry device, go to Contacts and open Options.
2.  Type:  rset (there isn't a field to type it in, just type it while Options is open.)
3.  Confirm that you want to wipe the contacts.

The address book will then appear blank, but will soon repopulate with the current contact information.

Solution -2

1. In the device options, click Advanced Options.
2. Click Service Book.
3. Highlight the service book - Desktop [ALP] or BlackBerry [ALP]*
4. Click the trackwheel or menu button
5. Click Delete.

Once this is done, just follow you step to "RSET"..

Now login to BB Server and right click on the user and re-send Service Book and it worked like a charm...