Based off your outlook 2010 screen shot, there are three Contacts - Outlook lists. if these lists contained the same data then you would have duplicates.

- Are you on an exchange server?
- When you export your contact list to .CSV file, from Outlook 2010 are they duplicated?

Outlook 2011 does not have an do not import duplicate function. However, outlook 2010 does. using this work around you could eliminate duplicates from a .PST or .CSV file.

Keep me posted