Outlook 2013 - contact duplicated in Outlook, but not on Windows Phone or at Outlook.com

Several weeks ago I updated from Outlook 2010 on my primary computer (Windows 8)  to Outlook 2013 (Office 365).  Previously, contacts and calendar were synchronized with my Windows Phone (7.5) via my Microsoft Account (Live.com, Hotmail.com, Outlook.com).  During the first few weeks, all was fine until June 7, 2013, when I noticed that all my contacts in Outlook had been duplicated, but that is the only location showing duplicates.  All is fine in the "cloud" and on my Windows phone.  I deleted the Exchange ActiveSync account from Outlook to "reset the shot clock."  When I reestablished the Exchange ActiveSync account, all was fine, no duplicates.  An hour or so later, I checked and the contacts had been duplicated again.  No problems with the calendar entries.  So, what might be causing the contacts to be duplicated and how do I resolve the issue?  Many thanks in advance for technical insight!
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bbaumbergerConnect With a Mentor ConsultantAuthor Commented:
I've been traveling for a few weeks, the reason for my delayed response.  The duplicate contact problem occurred on my desktop computer.  When traveling, I often copy my Outlook.pst file to my laptop computer, something I did recently.  Interestingly, when I copied the Outlook.pst file back to my desktop computer, the duplicate contact issue was resolved - no more duplicates.  I had been expecting to create a new Outlook profile, but will not do so since the simple task of copying the Outlook.pst file to another computer, then back to the desktop computer resolved the issue - a very pleasant surprise!
Blue Street TechLast KnightsCommented:
Hi bbaumberger,

I would first off call Microsoft Support. If it is a business account you should have free support.

When are you noticing the duplicate contacts? Are you seeing them in the same contact folder? Can you provide a screenshot? Can you duplicate this on another machine?

Typically, this is a delegate issue I've seen in Exch 2010 but not in 2013. When there are issues with the server you will tend to see them spawn into OWA and other devices, so when you say you "reset the clock", the procedure for doing so can be accomplished multiple ways. Make sure you follow these steps to remove your Outlook Profile. Close Outlook, go to Control Panel > click on Mail. In the Mail dialogue box select the default profile and click Properties > Data Files and select the default data file and click Open File Location. Once in the directory, highlight and delete all contents.

WARNING: This assume you are fully sync'd with Exchange.

Then click Close on the Account Settings dialogue box, close the Mail Setup dialogue box. Now remove the profile in the Mail dialogue box by selecting the profile and clicking Remove. Click OK and reboot your PC.

Once rebooted setup your Outlook profile. Let me know how it goes. Thanks!
bbaumbergerConsultantAuthor Commented:
I also posed the question to Microsoft Support, and they, too, recommended the recreation of my Outlook profile.  Although my contacts and calendar are synchronized across platforms via an Office 365 Exchange account, my profile includes several email accounts, a mix of old POP accounts and IMAP.  Due to upcoming commitments, I will not recreate the Outlook profile until mid-July 2013, at which time, I will convert my entire email environment to  full Outlook Exchange and IMAP as appropriate for improved cross-platform functionality.  I will update this problem report at that time.  Thanks for your advice.
Blue Street TechLast KnightsCommented:
I hear you...I used to be there...with multiple accounts on various platforms so I totally understand not wanting to just "re-create" your profile, but I was able to streamline and do some other things to consolidate my accounts and man its better, simpler and when issues come up you can just strip it down and build it up quickly. Thanks for the update. I look forward to working with you on this. Talk to you then!
bbaumbergerConsultantAuthor Commented:
I am accepting my solution as the best one because it resolved the issue without extra effort.  Thanks to all who contributed their suggestions!
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