"Already added" failure to export contact using Outlook Plugin

"Already added" failure to export contact using Outlook Plugin

In my evaluation phase for CRM, I exported all of my contacts to Zoho using the Outlook plugin.  I subsequently deleted them all from CRM, but now whenever I try to export one again, the operation fails with the message "already added."  I tried permanently deleting a contact from the Recycle Bin (I am the administrator) but that didn't help.  What can I do to fix this problem?