Usernames appearing twice


I got an issue that is bothering me a lot, i installed the Openfire in a linux server (Debian 7) and I’ve populated the database with my old database from the older server (That already had the username/password of all users). I did it from the plugin (Export/Import) at the admin console, and it worked fine. But i had to update the database, and i did it again. It appeared some warnings (That already exists some users, but i thought it was OK). So … After the second Import from the old database, now my Spark Client is showing the usernames twice when i try to search (ctrl F). Note that in the admin console there is no duplicate users.